搜题请搜索小程序“爱下问搜题”
问题 单项选择题

当胀接管子的硬度高于管板的硬度时，应将管子端部进行低温退火处理，以降低其硬度，提高塑性。对碳钢管，其退火温度为______℃。

A．500～550

B．600～650

C．650～700

D．750～800

答案

参考答案：B

阅读理解

Dear Zhang Qian,

Thanks for your letter. You want to know about my favorite sport and instrument(乐器). Now let me tell you. I like swimming very much, and I like volleyball, basketball, and ping-pang, too. Swimming is my favorite sport. I am good at playing the guitar and the violin, too. My favorite instrument is the violin. I often play the violin on weekends. What about you? What’s your favorite sport? Do you like to play the violin or the guitar? Please write to me soon.     

Yours,  

Li Ping

小题1:This is ____________.

A．a message

B．an ad(广告)

C．an e-mail

D．story小题2:______ is Li Ping’s favorite sport.

A．Swimming

B．Running

C．Jumping

D．the violin小题3:_______ is Li Ping’s favorite instrument.

A．guitar and Piano

B．guitar and violin

C．piano and violin

D．the violin小题4:Li Ping often plays the violin on ________.

A．Monday

B．Friday

C．Saturday and Sunday

D．weekdays小题5:Li Ping doesn’t like ________.

A．basketball

B．soccer

C．volleyball

D．Ping-Pong
查看答案
单项选择题

婴幼儿肺炎首先出现的病理生理改变是()

A．高碳酸血症

B．低氧血症

C．呼吸性酸中毒

D．代谢性酸中毒

E．混合性酸中毒
查看答案