The use of bamboo in science and technology is really exciting. In the Warring States period, Li Bing     1     (lead) the local people to build the Dujiang Weir, the first irrigation network in the world,     2     bamboo played an important role. During the Han dynasty, the Sichuan people successfully sank     3     1,600-meter-deep well with thick bamboo ropes. This technology didn’t spread to Europe     4     the 19th century and in 1859 Americans sank the first oil well in Pennsylvania by     5     (employ) the technology.

Papermaking     6     (be) one of China’s four ancient great inventions. In the Han dynasty, people began to use bamboo     7     (make) paper, which was of excellent quality and fair price. Even now it is considered as one of the important materials in papermaking. Some of the Xuan paper for traditional Chinese painting is also made     8     bamboo.

In the Yuan dynasty, a man     9     (plan) to send a person on the chair to space tied a big bamboo tube filled with gunpowder onto each of the four legs of a chair. Although it appears amusing, it is regarded as the     10     (early) “manned rocket design”.

The Amazon rainforest is home to a great     1    (various) of plant life; however, its soil is    2       (surprising) poor in nutrients. In fact, the soil in the region cannot support agriculture for more than a few years. If a scientist is shown a report     3    (list) the nutrients of that soil, he or she will probably think that only desert plants can survive in it! Then why is the soil so poor in nutrients? For one thing, the rainy season has     4     impact on the soil. In this season, the water level can rise to more than 12 meters.     5     the water goes away, it takes away the nutrients in the soil. For another thing, due to the Amazon’s hot climate, it is difficult for the soil     6    (build) enough nutrients. Dead plants and animals     7    (break) down more quickly. The nutrients are soon taken in by the roots of the plants deep     8     the ground. As a result, most of the forest’s nutrients are locked up in the plants     9    (them), thus allowing them to grow at a(n)    10    (believable) speed.