What are the tallest plants in the world? Many people would say that giant redwood trees of California. Actually, the tallest plants are in the oceans. These are seaweeds that grow almost seven hundred feet tall.
Compared to this height, the giant redwoods are pygmies of only four hundred feet. To get some idea of these heights, consider the Statue of Liberty. This huge figure rises only three hundred feet.
1. The passage can be entitled __________.
A. Redwoods in
B. The Statue of
The Tallest Plants
We think of a flood or an earthquake as a natural disaster. To many of nature' s animals, however, the greatest disaster is the coming of large numbers of humans. When settlers came from the East to America' s great western plains, they killed millions of bison, poisoned the prairie dogs, and shot the coyotes.
All this upset the area's balance of nature. For the animals, it was worse than a flood or earthquake.
2. Which of the following is the best title for the passage?
A. Nature Balance
B. Floods and
C. American Settlers
Humans--a Disaster to Nature
At this time the state of South Carolina was having hard times. Year after year the soil had been planted to the same crop. It was farmed by uneducated and careless slaves, and the planters knew little about soil
conservation. Because the soil was beginning to wear out, crops were smaller. The younger people were not satisfied to raise cotton on the poor soil of the old South. Many of them moved westward and started cotton plantations
in Alabama and Mississippi. What was more, so much cotton had been shipped to factories in England and New England that they had as much cotton as they could use. This brought the price of cotton down. More and more slaves were needed to work on the new and large plantations, and higher and higher prices were demanded for them. Planters found their expenses rising and their incomes from the sale of cotton reduced. Hard times had come to South Carolina.
3. The subject of this passage is __________.
difficulties of South Carolina
that the planters knew nothing about farming
that the soil in South Carolina was not good
the causes of hard times in South Carolina
4. Which of the following sentences can summarize
the main idea of the passage?
Hard times had come to South Carolina.
Planters found their expenses rising and their incomes from the sale of cotton
The soil was farmed by uneducated and careless slaves.
More and more slaves were needed to work on the new and large plantations.
When a piece of paper burns, it is completely changed. The ash that is left behind does not look like the original piece of paper. When dull-red rust appears on a piece of tinware
(锡制品), it is quite different from the gleaming tin. The tarnish that forms on silverware is a new substance unlike the silver itself. Animal tissue
(组织) is unlike the vegetable substance from which it is made. A change in which the original substance is turned into a different substance is called a chemical change.
5. The author writes this passage to tell us _________.
A. how paper burns
that dull-red on tinware is unlike tin itself
that animal tissue is different from plant's
D. what a
chemical change is