问题
单项选择题
可使运动变得省力的是
A.加长阻力臂或缩短力臂
B.加长阻力臂或力臂不变
C.缩短阻力臂或加长力臂
D.加长力臂或阻力臂不变
E.缩短力臂或阻力臂不变
答案
参考答案:C
可使运动变得省力的是
A.加长阻力臂或缩短力臂
B.加长阻力臂或力臂不变
C.缩短阻力臂或加长力臂
D.加长力臂或阻力臂不变
E.缩短力臂或阻力臂不变
参考答案:C
请根据句意从方框中选择合适的动词,并用其适当时态填空,使句子通顺。
小题1:She just_ _ that people in the west have 12 star signs. 小题2: My father ______ to celebrate my birthday with me several times but never did it. 小题3:If I have time, I my grandparents in the countryside this weekend. 小题4: My penfriend to my e-mail every week. 小题5:一Can you hear some students singing in the hall? 一Yes. Our school _________ a red-song competition there. |