It’s very important for a student to ________ a good state of mind while taking the college entrance examination.
7. When you read the book, you’d better make a mark ______ you have questions.
8. I didn’t see your sister at the cinema. If she ______, she would have met my brother.
9. _____ all behavior is learned behavior is a basic assumption of social scientists.
10. By the middle of the 21st century , the vast majority of the world’s population ________ in cities rather than in the country.
11. It is because people are likely to stay indoors ______ the virus can spread easily ______ people often catch colds.