人工拆除施工应从上至下、逐层拆除分段进行,不得()作业。
参考答案:垂直交叉
属于酸碱两性的生物碱是()
A.可待因
B.吗啡
C.秋水仙碱
D.莨菪碱
E.麻黄碱
Mother, together with her children , ______ to the hospital.
A.were sent
B.are sent
C.was sent
D.have been sent