高三英语备考总复习人教版必修4同步练习：4-2_高考复习指南

高三英语备考总复习人教版必修4同步练习：4-2

　　Agriculture has a long history in China. Much of the wisdom__1__by early Chinese scientists is still useful for farmers and gardeners today. One of China's early__2__scientists was Jia Sixie, who lived in the sixth century AD. He spent his time doing__3__into agriculture. He collected information, studied it, did experiments and learnt from the__4__of farmers.

　　Around 540 AD, he wrote a book called Qimin Yaoshu. The book is about both farming and__5__. It includes advice on the following__6__： growing green vegetables and fruit trees, keeping animals, and fish in lakes. There are also__7__for making wine. Jia Sixie's book is a(n)__8__guide for farming. Firstly, as a farmer you should do things at the right time of the year. If you sow seeds and__9__young plants in the fields at the correct time of the year, your work will be less and__10__will be better. But if you__11__nature and do

　　things at the wrong time of year, you will have to do more work

　　and the results will not be so good. The__12__of the soil is also

　　very important. Examine the soil on your farm__13__. If the condition of your soil is not good, you should improve it. Before sowing or planting crops, you must clean rough ground and__14__ weeds. Let sheep or cows walk on the land to__15__the weeds or eat them. The best harvest is reached when farmers__16__the crops in their fields. For example, do not plant rice __17__in the same field. But if you plant rice in a field one year and wheat in the field the next year, you will__18__good crops. Other scientists said that wheat should be planted with__19__ between the plants, but Jia did experiments and __20__that planting wheat close together is better.