1 . Some aspects of a pilot's job ________ be boring, and pilots often   ________ work at inconvenient hours

A．can, have to

B．may, can

C．have to, may

D．can, must

2 . Teachers have to constantly u________ their knowledge in order to keep up with the times and maintain their professional competence. (根据首字母单词拼写)

3 . Before you give the water to your baby nephew, you have to ________ (煮沸) it first. (根据汉语提示单词拼写)

4 . You __________ __________ take TOEFL or ELTS test if you want to study abroad. (用适当的词填空)

5 . I explained it to her again and again but she still couldn’t understand, so I __________ write it down. (用适当的词填空)

7 . John didn’t have much money, so he ________ ________ (不得不) work part-time to cover his living costs. (根据汉语提示完成句子)

9 . The factory finally had to __________(促进，推销) sales of its products by lowering prices. (根据汉语提示单词拼写)