【单选题】_______as an Olympic event, a sport must be played in at least 75 countries on at least 4 continents.
【单选题】To be elected to the Senate a person must______.
A.
be at least 25 years old
B.
be at least 30 years old
C.
have been a citizen for seven years
【单选题】Which of the following did the woman NOT mention about the production of the armchairs?
【单选题】The lazy boy ate the _____ food, but did the _____ work. [ ]
【单选题】湿式气缸套的冷却效果比干式气缸套的冷却效果 ( ) 。
【单选题】Which of the following does the passage mention as necessary for both the production of oxygen by photodissociation and the production of oxygen by plants?
【单选题】湿式气缸套的冷却效果比干式气缸套的冷却效果()。
【判断题】湿式气缸套比干式气缸套冷却效果好,但是使用这种缸套的气缸体刚度差,易于漏气、漏水。