题目

被子植物开花传粉后，受精的部位是（ ） A . 花药 B . 花萼 C . 子房 D . 花瓣 答案：CThe boy said _____ couldn't he work out the problem but his teacher didn't know how to do it. [     ]A. though　 B. never　 C. hardly D. not only