二、用括号内所给词的适当形式填空。
1. I didn't go, because I (be) afraid of my mother's illness.
2. If you (get) up late tomorrow, take a taxi to school.
3. If you run slowly, you (not catch) up with me.
4. I (go) to take a walk in the park if the weather is nice.
5. The boy is so strong because he often (go) to do some training after school.
6. We all (believe) Mike because he is such an honest man.
7. David (not go) with you unless you tell him the truth.
8. Since everyone ______ (be) here, let's begin our meeting.
9. If you (not make) a plan before you set off, you will make mistakes.
10. Qian Sunli (not win) first prize unless she keeps training hard day after day.

1. was 2. get 3. won't catch 4. will go 5. goes
6. believe 7. won't go 8. is 9. don't make
10. won't win

三、完成句子。
1. 由于时间晚了，我现在必须回家了。
it is late, I must go home now.
2. 如果你有任何麻烦，请询问人工智能。
you have any trouble, please AI.
3. 他昨天没去上学，因为他感冒了。
He go to school yesterday he caught a cold.
4. 因为她很紧张，所以她无法完成那篇演讲。
she was nervous, she couldn't finish that speech.
5. 如果你对别人友好，你将会交到更多好朋友。
you are friendly to others, you more good friends.

1. Since 2. If; ask 3. didn't; because 4. Because
5. If; will make

四、选词填空。
if unless because since as when
Growing up is never easy, but it is full of beautiful memories. Many teenagers feel worried about their studies and future. You may want to give up 1 you meet difficulties. It is not good for your growth. If you want to be better in the future, you shouldn't give up at any time. You should keep trying 2 you want to make your dream come true. You won't improve quickly 3 you keep practising every day. It is the best way to make your skills better day by day. It is unwise to lose heart 4 you fail once or twice.
Growth isn't easy, but difficulties can make you grow up to be a true man. 5 you are growing day by day, you are becoming stronger and braver. Don't be afraid of challenges 6 they can make you better. 7 you learn to face problems by yourself, you will really grow up. 8 you have tried your best, you have nothing to regret. Value the time 9 you are young, 10 youth is the most wonderful time in our life.
1. 2. 3.
4. 5. 6.
7. 8. 9.
10.

1. when 当你遇到困难时，就想放弃。
2. if 如果你想实现梦想，就应该不断尝试。
3. unless 除非你每天坚持练习，否则你不会进步很快。
4. if 如果你失败一两次就灰心，是不明智的。
5. As 随着你一天天成长，你正变得更坚强、更勇敢。
6. because 不要害怕挑战，因为它们能让你变得更好。
7. If 如果你学会独自面对问题，你就会真正成长。
8. Since 既然你已经尽力了，就没有什么可后悔的。
9. when 在你年轻的时候珍惜时间。
10. because 因为青春是人生中最美好的时光。