居民用电报装计量验收从安装到验收的时间间隔不超过（）个月。
A.半
B.一
C.二
D.三
参考答案：D
— I am sorry that I forgot to type your letter.
— _____. I can type it myself. [ ]
A. Take your time
B. You're welcome
C. Don't worry
D. It is up to you
下面那种是METROSITE基站的交流电源模块（）。
A、PSUA
B、PWSB
C、HVSD
D、CSUA
