题目内容
1. Many ( discover) have changed our life. |
1. discoveries
数学奥赛暑假天天练南京大学出版社系列答案( ) 1. —What a brave girl! —Yes. She no longer her parents though she’s so young. A. depends for B. feeds on C. feeds for D. depends on |
阅读短文，从方框中选择适当的词并用其正确形式填空，使短文通顺、意思完整。
The compass is very 1 for guiding ships and planes. Hikers often need a 2 ，too. A compass will always make it possible for you to know where is the north. The compass is a special magnet (磁体）. The Chinese were the first people to use the magnet 3 a compass. They first used compasses to guide their ships 4 the years 100 BC and AD 100. Their compasses were simple and not convenient. To make their compass,these early Chinese people placed the magnet needle (磁针)on soft wood and then put them in a 5 of water. The floating (不固定的） magnet turned easily,and made itself with the directions,north and 6 Later the Chinese invention was put together with a Babylonian (巴比伦人的）invention,the degree. A compass points out directions 7 to degrees. There are sixteen main points on a compass. Each main point is the 8 as a certain number of degrees. North on the compass,for example,is 0°C,east is 90Tl , and so on. Compasses worked 9 on wooden ships. But when metal ships appeared in the 1800s,the simple magnetic compass was not correct any more. Many kinds of new compasses begin to be 10 for sailing. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. |