【单选题】同分异构现象在有机化合物中是非常普遍的。下列各组化合物中互为同分异构体的是 ①CH 3 CH 2 CH 2 CH 3 和(CH 3 ) 2 CHCH 3 ; ②CH 3 CH 2 OH和CH 3 CH 2 CH 2 OH; ③CH 3 COOCH 2 CH 3 和CH 3 CH 2 CH 2 COOH; ④CH 3 CH=CHCH 3 和CH 3 CH 2 CH=CH 2 ; ⑤ ...
【多选题】下列各组化合物中互为同分异构体的是()。
【单选题】下列各组化合物中互为同分异构体的是.( )
【单选题】听力原文:W: Can you speak up a little? I'm having difficulty hearing you. M: All right. Is that better? Q: What can we conclude from the talk? (4)
A.
The woman doesn't like the man.
B.
The man tries to speak more loudly.
C.
The man doesn't want to speak up.
D.
The woman has no problem hearing the man.
【单选题】某批发企业销售甲商品,第三季度各月预计的销售量分别为1000件、1200件和1100件,企业计划每月月末商品存量为下月预计销售量的20%,下列各项预计中不正确的是( )
【单选题】Man: Can you come over for dinner tonight? Woman: I'm up to my ears in work, so I'll have to take a rain check. Question: What does the woman mean?
A.
She wants to check the weather before deciding.
B.
She has a problem with her hearing.
C.
She'd enjoy coming to dinner another time.
D.
She wants the man to help her with some work.
【简答题】完形填空。 'I can't believe what I'm hearing!' I thought to myself. Jeff was the last candidate (候选人) for president of Student Council. My best friend Tony came to me and said. 'I'm sorry, Mike. I really t...
【单选题】听力原文:Hello, Ms. Lee. This is Aaron Parks from Axis Corporation. I'm calling to let you know that your presentation yesterday impressed us all. We'd like you to send us a price quote for the Branden pr...
A.
A new product to be launched,
B.
An upcoming presentation.
C.
A date for completion of work.
【单选题】GABA转变成下列____形式后才进入三羧酸循环