娱乐效能是由两个途径来实现的:参与运动与()。
A、运动技巧
B、运动竞赛
C、掌握技能
D、观赏运动
参考答案:D
正压式空气呼吸器气瓶的使用压力不得低于()。
A.20Mpa
B.25Mpa
C.26Mpa
D.28Mpa
There have been many()in their marriage but they still love each other.
A.right and wrong
B.back and forth
C.ups and downs
D.right and left