2014年4月19日中国大陆托福考试全真试题英文还原

　　Reading

　　①

　　Over the years, humanities never stopped to ponder over how the universe evolved and have developed a variety of theories, among which the big bang theory and steady state theory prevailed. Both of the two theories are based on the fact that the universe is continuously expanding. However, the scientists have discovered that the universe looks the same from different cosmic position, which aroused more fierce debates on the authenticity of the two theories.

　　Georges Lema?tre first proposed (in 1927) what became the Big Bang theory in what he called his "hypothesis of the primeval atom". Over time, scientists built on his initial ideas of cosmic expansion and that this expansion could be traced back to the cosmic origin - a starting point for space and time that Lemaitre called "the day without yesterday" -- to form the modern synthesis. The Big Bang theory believes that the Big Bang occurred approximately 13.82 billion years ago, which is thus considered the age of the universe. At this time, the universe was in an extremely hot and dense state and was expanding rapidly. After the initial expansion, the universe cooled sufficiently to allow the formation of subatomic particles, including protons, neutrons, and electrons. After billions of years, the universe, as the big bang theory suggested, continues to expand, which caused the decrease in density and fall in temperature.

　　In early twentieth, another theory called steady-state theory emerged and caught up public attention. The idea was then revised in 1948 by Fred Hoyle, Thomas Gold, Hermann Bondi and others. The steady state theory of Bondi and Gold was inspired by the circular plot of the film Dead of Night, which they had watched together. Theoretical calculations showed that a static universe was impossible under general relativity, and observations by Edwin Hubble had shown that the universe was expanding. The steady state theory asserts that although the universe is expanding, it nevertheless does not change its appearance over time (the perfect cosmological principle); it has no beginning and no end. To explain the theory, scientists proposed that new matter like hydrogen, despite the expansion of the universe and the decrease in density, is continuously created, which kept the universe static. And the hydrogen is created so slowly that it is difficult to observe.

　　Problems with the steady-state theory began to emerge in the late 1960s, when observations apparently supported the idea that the universe was in fact changing: quasars and radio galaxies were found only at large distances (therefore could have existed only in the distant past), not in closer galaxies. Whereas the Big Bang theory predicted as much, the Steady State theory predicted that such objects would be found throughout the universe, including close to our own galaxy. Finally, the debate was settled with the triumph of the Big Bang theory.

　　②Seaweeds

　　Seaweeds are a fascinating and diverse group of organisms living in the earth's oceans. They have a amount of 2% of the ocean floor. You can find them attached to rocks in the intertidal zone, washed up on the beach, in giant underwater forests, and floating on the ocean's surface. They can be very tiny, or quite large, growing up to 30 meters long. There are two effects that effect their growth -the sunshine and the temperature.

　　Although they have many plant-like features seaweeds are not true vascular plants; they are algae. Algae are part of the Kingdom Protista, which means that they are neither plants nor animals. Seaweeds are not grouped with the true plants because they lack a specialized vascular system (an internal conducting system for fluids and nutrients), roots, stems, leaves, and enclosed reproductive structures like flowers and cones. Because all the parts of a seaweed are in contact with the water, they are able to take up fluids, nutrients, and gases directly from the water, and do not need an internal conducting system.

　　Like true plants, seaweeds are photosynthetic; they convert energy from sunlight into the materials needed for growth. Within their cells seaweeds have the green pigment chlorophyll, which absorbs the sunlight they need for photosynthesis. Chlorophyll is also responsible for the green coloration of many seaweeds. In addition to chlorophyll some seaweeds contain other light absorbing pigments. These pigments can be red, blue, brown, or golden, and are responsible for the beautiful coloration of red and brown algae.

　　Instead of roots seaweeds have holdfasts, which attach them to the sea floor. A holdfast is not necessary for water and nutrient uptake, but is needed as an anchor. Holdfasts are made up of many fingerlike projections called haptera.??The stalk or stem of a seaweed is called a stipe. The function of the stipe is to support the rest of the plant. The structure of the stipe varies among seaweeds; they can be flexible, stiff, solid, gas-filled, very long (20 metres), short, or completely absent.??The leaves of seaweeds are called blades. The main function of the blades is to provide a large surface for the absorption of sunlight.

　　In some species the blades also support the reproductive structures of the seaweed. Some seaweeds have only one blade, which may be divided, while other species have numerous blades.??Many seaweeds have hollow, gas-filled structures called floats or pneumatocysts. These help to keep the photosynthetic structures of the seaweed buoyant so they are able to absorb energy from the sun.

　　③Building the Nest Together

　　Building nest is complicated business. Every year after breeding grounds, a bird's first order of business is to eat. After refilling their energy supplies and meeting up with a fella, the female birds will immediately start to build a nest. To build the nest together has many benefits.

　　To build the nest on the islands would prevent it eating by other animals. When building a nest, the female bird must choose the perfect location. Female birds do not like to use regular bird house as they are too confining. She will need a good sold base like in a "Y" or crossed branches of a tree or bush. You may see her test the strength of a prospective nest site by repeatedly landing on it and clinging to it. A place with leaves over top to shelter from rain and sun is ideal because if the nest gets above 96 degrees Fahrenheit the little hummingbird eggs will be too hot to hatch. Since temperature is such an issue in raising, many female birds may prefer higher altitudes and locations close to bodies of water where the weather is cooler.

　　When the predators come, they can fight together. Female hummingbirds will need nesting material to make her nest. She likes to use nice soft material like moss and lichen. The spider webs make terrific glue for the nest, allowing the nest to stretch and be flexible as the baby hummingbirds grow. The spider webs also make it easier for the mother hummingbird to repair the nest when damaged or when kids do what kids do. While building the nest, the female hummingbird will try to camouflage it as much as possible by using small sticks, seeds. She will make sure the lighter parts of the nest are in the sun, while the darker parts of the nest are in the shade, blending it in with the surroundings.

　　When a mother hummingbird is gathering the materials for her nest, she will carry the items in her beak. When she arrives at the nest, Momma Hummingbird will painstaking tuck the material into the fork of the branches to make the base of her nest. When she carries the spider webs to the nest, you will notice them all around her beak, under her chin, and across her breast. She will use her chin and body to press the spider webs and material into her nest so that every piece will go exactly where she wants. That is against a building you may even notice the mother hummingbird gathering paint chips to help camouflage the nest against the building.