27.(2011 江苏南京，6) They will try their best in the Dragon Boat Racing       they may fail.

   A. if   B. although   C. unless   D. until

26.( 2011 重庆，25 ) John,work hard       you will make much progress.

   A. or   B. nor   C. but   D. and

25.( 2012 浙江宁波，29) Why didn’t you try your best to get on the subway?

—I tried to,but it started moving       I could get on it.

   A. before   B. after   C. since   D. if

24.(2012 青海西宁，24) — This dress was last year’s style.

一I think it still looks perfect       it has gone out this year.

   A. so that   B. as if   C. even though   D. ever since

23.(2012贵州黔东南，24) We can’t pass the exam       we study hard.

   A. because   B. and   C. unless   D. or

22.(2012 安徽，34) —Tom isn’t feeling very well.

—He seems to have a cold       the weather changes suddenly.

   A. before   B. so   C. because   D. though

21.( 2012 上海，37) Martin and his friends didn’t eat up all the food they ordered,       they took the rest away.

   A. for   B. or   C. so   D. as

20.(2012 贵州铜仁，35) The bus driver always says to us ,“ Don’t get off       the bus stops."

   A. when   B. while   C. until   D. if

19.(2012 山东济南，25) 1 won’t take part in Julie’s birthday party       I am invited.

   A. unless     B. after

   C. because   D. if

18.( 2013 天津，28) You will be late for school       you don't get up early.

   A. but   B. if   C. and   D. or