电石与水反应完的产物显()性。A.酸性 B.碱性 C.中性

题型:单项选择题

问题:

电石与水反应完的产物显()性。

A.酸性

B.碱性

C.中性

考点:聚氯乙烯聚氯乙烯初级考试聚氯乙烯初级考试题库
题型:单项选择题

阅读理解。

     Bob always took the newspaper to Grandpa White's home before going home. Grandpa White's was

 at the end of the road. Bob liked Grandpa White. He was often waiting for him near the front gate with

 sweets or a nice cake. Besides, He often asked Bob about things he was doing, what he was going to do

  for the summer and what he liked to do.

     The thing that Bob didn't like about Grandpa was his never-ending stories about his boyhood (童年) in

 California. Bob was never asked to hear about Grandpa's boyhood, but he couldn't get away.

     After Grandpa's wife died in October, Bob could see that Grandpa was lonelier than ever. He would

 often join Bob halfway along the road and walk along with him as he gave out the newspapers. Grandpa

  seemed to have all day, and Bob was often late giving newspapers to his customers (订报者). Bob didn't

  want to complain, but the customers were unhappy.

1. When he took the newspaper to Grandpa White, Bob would often receive _____.

    A. old newspaper

    B. sweets or a cake

    C. some money

    D. stories

2. Bob could do nothing when _____.

    A. the customers got their newspapers late  

    B. Grandpa began to tell him about his boyhood

    C. he saw grandpa feeling lonely          

    D. Grandpa asked him about the things he was doing

3. The passage mainly tells us that _____ .

    A. Bob was still a child

    B. Grandpa liked to tell stories

    C. the customers sometimes got angry

    D. lonely people need other people

题型:单项选择题

2010年1月15日,我国出现了千载难逢的日环食天象。在云南滇西某时刻观察到的日环食如图所示,解释此现象用到的物理知识是

[ ]

A.光的直线传播

B.光的反射

C.光的折射

D.光的色散

题型:单项选择题

The Internet is really ______ to us. We can easily find the information we need.[ ]

A. safe

B. hard

C. boring

D. useful

题型:单项选择题

诱发与加重心力衰竭的最主要、最常见诱因是()

A.肺部感染

B.过度劳累

C.情绪激动

D.原有心脏病加重

E.过多过快输血输液

题型:单项选择题

分级除尘效率

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