单选题：The reason why he failed is _____ he was too careless. [ ]A..

_____ many millionaires recognize they are doing better than average investors, some factors haveforcedthem to reassess what the term "wealthy" means to them.A. Because B. While C. As D. Since

—Why，I didn’t get you on the phone.—We ________football on the playground when you phoned.A．must be playingB．must playC．must have playedD．must have been playing

The bike hit the tree _____ I could get off.A. as B. beforeC. until D. while

The young couple are trying to save as much as possible _____ they can afford a flat by the end of next year.A. so that B. even though C. in caseD. as if

_____ you've got a chance, you might as well make full use of it.A. Now that B. After C. Although D. As soon as