Liu Xiang has failed over and over again in the past years. And that’s _________ he succeeds.

Did you get your report card today, Susan? — Yes, I did. I didn’t do well in science. Because it’s too _______.

Ann helps Lily with her homework ______ eight o’clock ______ Sunday. [ ]

Although it seemed to be ______ painful experience, he still found it ______ fun.

．He is so addicted to computer games that_______seems to be no chance of talking him into quitting.