完成句子（共10小题；每小题2分,满分20分）
On the phone he told me that it was the first time that his parents  ______________________  him home alone. (leave)
他在电话中告诉我那是他父母第一次把他单独留在家中。
At one point we were so high ______________________________ cycling through the clouds.(find)
在某个时刻，我们置身高处，我们发现自己（仿佛）在骑自行车穿越云层。
You had so much free time yesterday. You __________________________  a part in the activity organized by the school. (play)
昨天你有许多空余时间。你本应参与学校组织的活动。
He asked me whether I  ____________________________the class discussion the next day. (join)
他问我第二天是否将会参加班级讨论。
It was my sister _____________________________ find where the river begins.  (determine)
是我的妹妹决定要找到河流的源头。
After the disaster, workers were sent to build shelters for survivors _________________________in the earthquake.  (destroy)
灾难发生后，工人们被派去给那些在地震中家园被毁的人建起庇护所。
My teacher told me not to  ______________________the door when I left the classroom.  (lock)
老师告诉我离开教室时不要忘了要锁门。
Ever since last year, the number of people learning to drive _________________________ a lot because of the improvement of people’s living standard. (increase)
由于人们生活水平的提高，学开车的人数从去年以来大幅增长。
Mike told me that there was a time __________________________ going over his lessons. (stay up)
迈克告诉我曾经一段时间他熬夜复习功课。
This is because in the early days of radio, those who reported the news _______________________excellent English. (expect)
这是因为在早期的电台节目里，人们期待播音员说讲好的英语。