爬式潜泳只用双腋()打水动作向前游进。
A.蛙泳
B.爬泳
C.蝶泳
D.侧泳
参考答案:B
You will believe me if you go and see the pyramids______ yourselves. [ ]
A. by
B. to
C. with
D. for
简述齿条推压传动方式的特点是什么?