感染是慢性支气管炎发生发展的什么因素（） A.唯一因素 B.重要因素 C.首发因素

Her watch _____ in her backpack.     [ ]

A. am

B. is

C. are

D. be

弹簧秤的秤钩上挂一个重2 N的物体，当弹簧秤与所挂物体一起匀加速竖直上升时，弹簧秤示数可能出现下列哪个图所示情况 

A．To call the community to donate more money after emergency takes place.

B．To provide financial help after the emergency takes place.

C．To be ready with emergent financial crisis.

D．To be ready for the financial needs of the community.

CMOS集成门电路的内部电路是由场效应管构成的。