DAO模型层次中处在最顶层的对象的是A．DBEngine B．Workspace C

下列哪项是普通感冒的临床症状

A．鼻塞、流涕

B．咽痒、咽痛

C．恶风或恶寒

D．周身酸楚不适

E．昏迷、惊厥

They have no idea at all______.

A．where he has gone

B．where did he go

C．which place he has gone

D．where has he gone

In case of any loss or damage, we will ______ a claim ______ agent at our port.

A. put forward, for


B. file, with
C. ask, with


D. lodge, to

联系自己的科学实际，谈谈如何从纷繁复杂的社会矛盾中提炼出具有学科价值的理论问题？

肺癌的发生与下列哪项关系最密切

A．环境空气污染

B．吸烟

C．职业致癌因素

D．肺部慢性病变

E．遗传因素