轴向力等于零处称为钻杆柱的中和点。钻杆柱中和点处的应力状态是()
A.纯扭;
B.压扭;
C.拉扭。
参考答案:A
根据要求改写句子。
1. There is a football match between Class One and Class Two. (用tomorrow改写句子)
There _______ _______ _______ _______ a football match between Class One and Class Two
tomorrow.
2. He does his homework every morning .(改为否定句)
He_______ _______ his homework every morning .
3. I’m going to take a plane to Beijing.(改同义句)
I’m going to go to Beijing _______ _______ .
4. My brother and I read in class every day.(把every day改为now)
My brother and I_______ _______ in class now.
5. The homework usually takes me 2 hours.(对划线部分提问)
_______ _______ does the homework usually _______ you ?
依照我国宪法规定( )是不属于集体所有的自然资源。
A.森林、草原
B.滩涂、荒地
C.矿藏
D.山岭