如图所示,A、B、C、D四个人做杂技表演,B站在A的肩上,双手拉着C和D,A撑开双手水平支持着C和D.若四个人的质量均为m,他们的臂长相等,重力加速度为g,不计A手掌与C、D身体间的摩擦.下列结论错误的是( ) A. A受到地面支持力为4mgB. B受到A的支持力为3mgC. B受到C的拉力约为mgD. C受到A的推力约为mg
The play Teahouse __________ by the famous Chinese writer Lao She.
wrote
was writing
was written
time flies!Our middle school life is coming to an end.
How
What
What a
Many tourists visit Hainan around the Spring Festival,because it's _______ too cold _________ too hot.
both...and
not only...but also
neither...nor
一Jerry,can you give me a hand?
一Just a minute.I ___________ an e﹣mail.
have sent
am sending
was sending
一I have less homework than before!
一Me,too.Now,we have enough time __________ sports.
do
doing
to do