三、用for或since填空
21. I have been learning English two years.
22. my last letter, I have heard from him twice.
23. The meeting has been going on about five hours, but it's still on.
24. She has written for magazines and newspapers she finished high school.
25. She has kept on watching the TV show it came out one month ago.

21.for 22.Since 23.for 24.since 25.since

四、汉译英(将下列括号中的汉语部分译成英语,注意使用适当的形式)
26. Alexander Bell the telephone in 1876.(发明)
27. tourists visit the Great Wall during the summer holiday.(数以千计的)
28. It is an amazing and experience to travel alone.(不寻常的)
29. My mother spends hours with me every Sunday.(几个)
30. Relax and take a break you feel tired.(无论何时)

26.invented 27.Thousands of 28.unusual 29.a couple of/several 30.whenever