这几个句子英语怎么翻译？

.当我赶到操场，他们正上体育课
when l reached the playground,they were having a PE lesson
2.他到电影院时，电影已经开始半个小时了
when he got to the cinema, the film has already begun for half an hour.

3.当我到车站时，车子已经走了
When I get to the bus stop,the car had already left.

4.随着日子一天天过去，天气变得越来越凉爽
as day by day,the weather becomes cooler and cooler .

5.晚上我在做作业时，爸妈在看电视
l was doing my homework when my parents were watching TV
6.走之前把作业交了
before leaving,please hand the homework
7.他每天完成作业后弹半小时钢琴
he plays the piano everyday after he has done his homework
8.明天我一见到他，就把这个好消息告诉他
.As soon as i see him ,i will tell him the good news.
9.他从大学毕业以来就一直在二中教书
Since graduating from the college, he has been teaching in NO.2middle school
10.我等你回来
l will wait for you
11.昨晚知道篮球赛结束我才睡觉
l wasn't go to sleep until the basketball finished
12.车未停，别下车
Don't get off the car before stopping.'
13.每当你离开学校，必须请假
You must ask for leave before leaving school
14.他每次感冒都头疼
He always has headache when catching a cold
15.如果明天下大雪，我们要做个雪人
.If it is snowing tomorrow,we should make a big snowman.
16.只要你更努力学习，你会取得
.If you study harder,you will get better .
17.假设你不来，我们将怎么办？
If you don't come ,what shall we do?
18.如果不下雨，我们去爬华蓥山
.If it doesn't rain,let's go climing
19.专心听讲，否则听不懂
If you don't listen carefully,you cannot understand.
20.那天我正睡觉，突然地震了
There was a earthquake when i was sleeping.

When I arrived playground, they are on physical education

2. Him to the cinema, the film has already started half an hour

3. When I went to the station, the car has gone

4. As day by day, the weather has become increasingly cool

5. Assignments in the evening I, the parents watching TV

6. Go before the operation paid

7. Every day he completed work for half an hour after the bomb Piano

8. I see him tomorrow, they told him the good news

9. Since graduating from college, he has been in the teaching of

10. I am waiting for you back

11. At the end of basketball I know only go to sleep

12. Vehicle did not stop, do not get off

13. When you leave school, must leave

14. Every time he is a cold headache

15. If tomorrow under the snow, we have to make a snowman

16. Even if you study hard, you will get a good result

17. Assuming you do not, we will be how to do �0�3

18. If we do not raining, we Qupa Huayingshan

19. Concentrate on listening to the lectures, or do not know how to listen

20. I was sleeping when suddenly the earthquake