1. The fact from some sports professionals________that two hours of outdoor exercise a week ________ especially helpful for one’s good condition.
A. show;are B. shows;is
C. show;is D. shows;are
【答案】：B
解析：本题考查主谓一致。主句主语是a survey，谓语动词应用单数形式；从句主语是two hours of outdoor exercise a week 表示一个整体概念，因此谓语动词也应用单数形式。
