在同频率交流电路中，电压与电流的相位差大于零，则 A．电压超前于电流 B．电流超前于

根据句意 ,用所给单词的适当形式填空 .

1. Maria tries __________ (drink) milk every morning.

2. Here are some __________(photo) of my family.

3. Billy goes to the beach with his friends three __________ (time) a month.

4. If you want to keep healthy, you should eat a __________ (balance) diet.

5. __________ (read) in bed or in the sun is bad for your eyes.

6. New Year's Day is very important in some __________ (west) countries.

7. It usually takes me about half an hour __________ (walk) to school.

8. Thanks for your __________ (invite).  I'd love to go to your birthday party.

9. Teddy has a __________(healthy) lifestyle than the other students in his class.

10. My proper ways of studying English help me get good __________ (grade) in exams.

美国的城市规划史，( )是最为关键的因素。

A．奴隶制被废除

B．社会福利政策进一步完善

C．公共工程建设

D．政府对私人财产权利实行控制的权力演变

在Windows 98环境下，系统支持F面4种文件系统：
Ⅰ．FAT12 Ⅱ．FAT16 Ⅲ．FAT32 Ⅳ．CDFS
硬磁盘存储系统可采用的文件系统为

A．Ⅰ和Ⅱ

B．Ⅱ和Ⅲ

C．Ⅲ和Ⅳ

D．Ⅰ、Ⅱ和Ⅲ

柏拉图为什么要哲学王治理国家？

调节喇叭嘴支架曲柄偏心距可改变喇叭嘴支架的（）。

A.高低位置

B.里外位置

C.距离

D.行程