在提升速度大于3m/s的提升系统内,必须设()。
A.防撞梁
B.托罐装置
C.防撞梁和托罐装置
参考答案:C
Sandy could do nothing but ______ to his teacher that he was wrong.
A.to admit
B.admitted
C.admit
D.admitting
下列药物中,不属四大怀药的是()
A.地黄
B.牛膝
C.山药
D.砂仁
E.菊花