51、I have been in the factory for two years.
52、It takes/took/will take sb. st. to do sth.  eg. It took me an hour and a half to work out the difficult problem. 
It takes me one and a half hours to go to school on foot.
53、I have two brothers. One is a worker.. The other is a doctor.
54、There are lots of children playing in the park.
Some are singing. Others are playing games.
55、There are fifty students in our class. Thirty are girls. The others are boys.
56、Let's make it 8:30/a little/a bit earlier
57、He is as tall as I/me.   He doesn't run as/so fast as I/me.
58、He is interested in the film.  The film is interesting.
59、Not everyone likes sandwich.= Everyone doesn't like sandwich. 
Everyone likes sandwich.  No one likes sandwich/None(None of them) like(s) sandwich.
60、I don't think he is right, is he?   He doesn't think you are right, does he?
( think, guess, except, suppose, imagine, believe.)
61、There is little water in the bottle, is there/There is a little water in the bottle, isn't there?
There are few books on the table, are there? There are a few books on the table, aren't there?
62、 Do you have one more to say?  There are another three mooncakes left.  Do you have one more to eat?
63、The lights are still on. He must be at home, isn't he? He must have come here yesterday, didn't he?
64、Do you mind my opening the door?
65、Everybody is looking forward to May Day with great joy.
66、He can't help crying.     
67、I am a student , aren't I?
68、What's he?=What does he do?=What's his job?  
69、Jim is short for James
70、Help yourselves to some grapes and watermelons.
71、We often go on a picnic/our first field trip/a long journey to the west of China.
72、I often see some students at school talking to each other in English.(see, find, watch, hear)
73、Sometimes we find them driving the tractors on the farm.
74、I think every minute counts.   
75、He was unhappy, wasn't he?