（）不适用于开挖停机面以下的土方。
A.正铲挖土机
B.反铲挖土机
C.拉铲挖土机
D.抓铲挖土机
参考答案：A
My mother was doing some ______ when her mobile phone ______ suddenly. [ ]
A. shoppers; is ringing
B. shopping; rings
C. shopping; rang
D. shopping; is ringing
阴阳转化的内在根据是
A．相互消长B．互根互用C．对立制约D．协调平衡E．相互交感
