按信号源进行分类主要有收音（FM/AM收音机功能）、磁带、（）、VCD、DVD、（）

—Miss Li, are we going to have a picnic tomorrow?

—Yes. But if it ______, we’ll do some reading instead.

A．will rain

B．rains

C．is raining

D．rained

骨梗死的X线表现为()

A．囊状及分叶状透光区

B．硬化斑块影

C．条带状钙化骨化影

D．绒毛状骨纹

E．骨外膜增生

The story book is so_      that I want to read it again.

[      ]

A. interest

B. interested

C. interesting

D. interests

报关企业1年内代理报关的货物因侵犯知识产权而被海关没收达3次的，适用C类管理。

RS-232C标准中逻辑0的电平为( )。

A．0V～15V

B．+5v～+15V

C．-3V～-15V

D．-5V～0V