[单项选择]TOEFL Reading Passage 2

The Mediterranean’s Killer Algae

1. Today there are many invasive species threatening ecosystems all over the world, but few are of as much concern as Caulerpa taxifolia.This species of green algae grows in long, thin blades similar in appearance to sea grass. Each individual alga is single-celled, with a length of up to a meter, they are some of the largest cells in the world. Algae contain chlorophyll and produce their own food through photosynthesis. Also they reproduce asexually, meaning that if an alga is cut in two each half wilt develop into a whole new organism.
2. Caulerpa taxifolia’s native habitats are the tropical waters of the Caribbean, south Pacific, east Atlantic, and Indian Ocean. However, in the 1970s, a new strain was bred in Europe to decorate exhibits in saltwater aquariums. The strain proved useful for this purpose, for it was able to grow more quickly,
A. the world’s largest algae.
B. the ability to make food on its own.
C. a slender, green appearance.
D. an invader of foreign ecosystems.

[单项选择]TOEFL Reading Passage 2

1. Today there are many invasive species threatening ecosystems all over the world, but few are of as much concern as Caulerpa taxifolia.This species of green algae grows in long, thin blades similar in appearance to sea grass. Each individual alga is single-celled, with a length of up to a meter, they are some of the largest cells in the world. Algae contain chlorophyll and produce their own food through photosynthesis. Also they reproduce asexually, meaning that if an alga is cut in two each half wilt develop into a whole new organism.
2. Caulerpa taxifolia’s native habitats are the tropical waters of the Caribbean, south Pacific, east Atlantic, and Indian Ocean. However, in the 1970s, a new strain was bred in Europe to decorate exhibits in saltwater aquariums. The strain proved useful for this purpose, for it was able to grow more quickly,
A. It was not known to scientists.
B. It did not flourish in a wide range of temperatures.
C. It was used primarily in freshwater aquarium exhibits.
D. It was found only off the coast of France.

[简答题]TOEFL Reading Passage 1

1. One of the most intriguing physical characteristics of snakes is their forked tongues. While this trait is also shared by some types of lizards, all snake species exhibit split tongues, which usually have a more pronounced fork than those of lizards. Any observer of snakes has no doubt noticed that they often stick their tongues out of their mouths, flick them up and down in the air, and then retract them. In fact, due to a slight indentation in the upper jaw, many species can protrude their tongues without even opening their mouths.
2. The explanation for this behavior remained unknown for centuries, giving rise to many folk superstitions. For example, the forked tongue has become synonymous with deceit, from the idea that two separate tongues would enable a creature to voice two contrasting ideas at the same ti

[简答题]TOEFL Reading Passage 2

1. Today there are many invasive species threatening ecosystems all over the world, but few are of as much concern as Caulerpa taxifolia.This species of green algae grows in long, thin blades similar in appearance to sea grass. Each individual alga is single-celled, with a length of up to a meter, they are some of the largest cells in the world. Algae contain chlorophyll and produce their own food through photosynthesis. Also they reproduce asexually, meaning that if an alga is cut in two each half wilt develop into a whole new organism.
2. Caulerpa taxifolia’s native habitats are the tropical waters of the Caribbean, south Pacific, east Atlantic, and Indian Ocean. However, in the 1970s, a new strain was bred in Europe to decorate exhibits in saltwater aquariums. The strain proved useful for this purpose, for it was able to g

[单项选择]TOEFL Reading Passage 1

1. One of the most basic elements of human life is the way in which we form social groups and interact with the members of those groups. According to sociologists, no one is ever entirely separate from the social networks that surround him or her, and the groups we belong to play an enormous role in determining how we see ourselves and our world. Early American sociologist Charles H. Cooley(1864-1929) defined two principal categories of human groupings, and his ideas are still widely accepted today. He termed them primary and secondary, based on the kinds of relationships individuals in the group share with each other.
2. In primary groups, we form what Cooley referred to as primary relationships. These are marked by strong, long-lasting emotional ties, feelings of intimacy and genuine concern for the well-being of the other person or people. Intan
A. less-developed nations.
B. individuals.
C. bonds.
D. primary groups.