双基限时练(十) Unit 4 Part Ⅰ
Ⅰ.单词拼写
1. He was interested in a________ and always stayed up at night to watch the stars.
答案 astronomy
2. On May 12, 2008, an v________ earthquake struck Wenchuan County, Sichuan, China.
答案 violent
3. Computer hackers have broken down security s________， raising questions about the safety of information.
答案 system
4. The mixture of gases that surround the earth is called a________.
答案 atmosphere
5. Forming a good habit of studying is ________ (基础) to one's achievements in the years to come.
答案 fundamental
6. He stuck to his ________ (理论) and it proved to be correct at last.
