（急）一道英语语法题

阅读理解。
Which country grows the most tea? The answer is India. It grows three times as much as China. Which country drinks the most tea? It's neither China nor Japan. It's Great Britain.
In the wild, tea plants may be 30 feet tall. But a plant grown for market is pruned(修剪).Pruning keeps the plant only three or four feet tall. This is an easy height for tea picking. Only the two top leaves of each
new shoot(芽)are picked. So to make money, tea plantations must be huge.
In general, there are two kinds of tea, black tea and green tea. They are made in different ways. When black tea is made, it loses nearly all of its healthy qualities. But green tea retains its healthy qualities. For
instance, it may prevent heart disease(病).
How did we get tea bags? The answer: by accident. People used to send tea in tin boxes. This was
expensive. Someone thought of a cheaper way. He sent tea in small silk bags. Customers would open the bag. They would put the leaves into a pot as usual. One customer put the bag into a pot. Then he just
poured hot water over it. And the tea bag was born.