任务型读写。阅读下面短文，根据所读内容在表格中的空白处填入恰当的单词。
注意：每个空格只填一个单词。
A simple water pump is helping to improve the lives of poor families in several Asian and African countries.
The treadle pump (脚踏抽水机) is based on a design developed in the 1970s by Norwegian engineer Gunnar
Barnes. It can be made locally and easy to build from bamboo or other wood and two metal cylinders (圆筒)
with pistons (活塞). The pistons go up and down as a person stands on lever (控制杆) devices, treadles, and
uses a natural walking motion.
How many hours a day the pump needs to be operated depends on the season and how much water is
needed for crops. It could be two hours a day or seven hours a day. Small children sometimes stand with their
parents on the treadles. Everyone in the family can take turns operating the pump.
Families using them ate more vegetables, because they were able to grow more to eat and to sell. Many of
these families also drank more milk, because they bought a cow with their added earnings. Men with treadle
pumps often no longer have to leave the farm to seek extra work in cities. The pumps can also improve
education. Farmers often use their extra earnings to buy books for their children or to pay for schooling.
A farmer in Zambia said he hoped to have enough money in three years, to buy a diesel-powered pump.
Then he could grow more crops over a larger area. But the world economic crisis has had an effect on some
farmers. Even some who were able to buy diesel pumps now do not have enough money to buy fuel. So they
are using their treadle pumps again.
