新加坡经济腾飞给亚洲广大发展中国家的主要启示是[ ]
A.制定适合本国国情的经济发展战略
B.选择先进的社会制度
C.发展耗能源、耗水、耗原材料的工业
D.大力发展出口加工工业
答案:A
Mark _____ have hurried. After driving at top speed, he arrived half an hour early. [ ]
A. needn't
B. wouldn't
C. mustn't
D. couldn't
下列泵中电动机要通过减速机构带泵工作的是()。
A.齿轮泵
B.水环泵
C.旋涡泵
D.往复泵