某有机物的结构简式为,它可以发生反应的类型有[ ] ①加成 ②消去 ③水解 ④酯

题型:选择题

问题:

某有机物的结构简式为,它可以发生反应的类型有[ ]

①加成 ②消去 ③水解 ④酯化 ⑤氧化 ⑥加聚

A.①②③④

B.①②④⑤

C.①②⑤⑥

D.③④⑤⑥

考点:羧酸的通性醇的通性酚的通性
题型:选择题

阅读理解。

     Most middle school students wear uniforms. Some students like uniforms, but others don't. However,

recently, a Japanese government survey (政府调查) shows that more students in Japan like uniforms

now because school uniforms are more fashionable (时尚的) than they were before.

     I surveyed some Japanese students about what they thought about school uniforms. I asked them,

"Do you like fashionable uniforms?" There were lots of different opinions (观点, 看法).

     Hiromi said, "I like school uniforms because I don't need to choose clothes every day. I think that

fashionable uniforms are good. My high school uniform is fashionable, but there is a problem. Fashionable uniforms are too expensive."

     Miki said that she didn't like fashionable uniforms because she didn't want to spend too much money

on uniforms. She thought that the uniforms should be changed(被改变). They should be cheaper and

easier to get.

     Mitsuaki said, "I don't like school uniforms because I want to look different. I also agree that

fashionable uniforms make many students want to wear uniforms in high school. If students like

fashionable uniforms, it is good. "

1. Do more students or fewer students like uniforms in Japan now?

    _____________________________________________________________________

2. What is the question of the survey?

    _____________________________________________________________________

3. How many students' opinions are there in the passage?

    _____________________________________________________________________

4. Why does Hiromi like school uniforms?

    _____________________________________________________________________

5. Why do students not like school uniforms?

    _____________________________________________________________________

题型:选择题

在图所示的电路中,R2为定值电阻,R1为滑动变阻器。在变阻器的滑片向右移动的过程中,图中的电压表,电流表示数及它们的比值的变化情况是(   )

 

A.电压表示数变小,电流表示数变大,比值变小

B.电压表示数变大,电流表示数变小,比值变大

C.电压表示数不变,电流表示数变大,比值变小

D.电压表示数不变,电流表示数变大,比值变大

题型:选择题

如图所示;水槽内盛有澄清石灰水,点燃 高低两支蜡烛,用钟罩将其扣在水槽内。实验中可以观察到哪些主要现象?(至少写出三条)

题型:选择题

某同学做探究牛顿第二定律的实验,使用的器材有:带滑轮的长木板、小车及往小车摆放的大砝码、细线、小盘及往小盘里放的小砝码、打点计时器等.

(1)他以小盘和盘内砝码的总重力作为细线对小车的拉力F,测出不同拉力F对应的加速度a值,并把各数据标在a-F坐标系上,发现它们都在一条直线的附近,这条直线不过坐标原点,如上图(甲)所示,产生这种情况的原因是什么?答:______

(2)经过调整后,该同学作出的a-F图象如图(乙)中的A所示,另一位同学使用同一套仪器作出的a-F图象如图(乙)中的B所示.则mA______mB(填“>”、“=”或“<”号)

题型:选择题

女性,16岁,要求治疗右上前牙。3个月前,右上中切牙外伤未及时就诊。检查:近中切角缺损,牙冠暗灰色,叩痛(-),电测验无活力。X线片未见根折线。该患牙的诊断应是()

A.外伤冠折

B.急性牙髓炎

C.慢性牙髓炎

D.牙髓坏死

E.急性根尖周炎

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