单选题 Having been attacked by terrorists, ________.

单选题 Children under 12 years of age in that country ________ be under adult supervision when is a public library.

单选题 He speaks English well indeed, but of course not _____ a native speaker.

单选题 The accident is reported to have occurred __________ the first Sunday in February.

单选题 The number of deaths form heart disease will be reduced greatly it people _______ to eat more fruit and vegetables.

单选题 I had to buy _________ these books because I didn’t know which one was the best.

单选题 Bill’s aim is to inform the viewers that cigarette advertising on TV is illegal, _______?

单选题 According to a recent U.S. survey, children spent up to 25 hours a week _________ TV.

单选题 The first use of atomic weapons was in 1945. and their power ______ increased enormously ever since.