35.Only when class began _____ that he had left his book at home.

　 A. will he realize　　　　 B. he did realize　

　 C. did he realize　　　　 　D. should he realize

34.There is no point _____ further. It won’t help much.

　 A. on explaining　　　　 B. to explain　　

　 C. of explaining　　　　　 D. in explaining

33.I find these problems are easy _____.

　 A. to be worked out　　 B. to work out　　

　 C. to work them out　　 D. to be worked them out

32.Nothing can stop a _____ student _____ his mind to give up his studies.

　 A. promised; to change　　　 　　

　 B. promised; changing　　　

　 C. promising; changing 　　 　　　

　 D. promising; to change

31.I’m _____ the guidebook, looking for information about Guangxi, where I’ll travel.

　　 A. looking　 　　　　　　　 B. scanning　 　　

　　 C. seeking　　　　　 　　　　 　D. arguing

30.It looked like rain last night, but it turned _____a fine day.

　 A. out　　 B. off　　 C. down　　 　　 D. up