将一根洁净的铁丝放硫酸铜溶液中，下列叙述正确的是（） A．溶液由蓝色变成红色

发布时间：2017-06-13 14:29 │ 来源：www.tikuol.com

题型：选择题

问题：

将一根洁净的铁丝放硫酸铜溶液中，下列叙述正确的是（　　）

A．溶液由蓝色变成红色

B．铁丝表面有红色物质生成

C．铁丝表面有气泡产生

D．反应后溶液的质量不变

考点：金属的化学性质

题型：选择题

完形填空。
Do you often watch TV? Maybe (也许) your l is "yes". Most children like watching TV 2 it's interesting and relaxing. They can also learn a lot and know 3 things about their country and the world. Of course, they can also learn over the radio. They can learn something quickly from those TV programs because they can hear and watch at the same time. But they can't see 4 over the radio. TV helps to open children's eyes. TV can open their minds. They can learn some better ways of 5 things. Many children are always 6 with their studies, so they watch TV only on weekends. 7 some children watch TV every night. They go to 8 very late and they can't have a good rest. And they will have less time 9 their lessons and fall behind other students. So when you want to watch TV, you must remember, "Study must come first." What do you 10 it?
( )1. A. ask ( )2. A. so ( )3. A. a lot ( )4. A. something ( )5. A. doing ( )6. A. free ( )7. A. And ( )8. A. the bed ( )9. A. do ( )10. A. think	B. answer B. because B. lot of B. anything B. to do B. busy B. But B. their beds B. does B. think of	C. question C. but C. lots of C. nothing C. do C. tired C. Because C. bed C. to do C. like	D. say D. and D. a lots of D. someone D. does D. friendly D. or D. beds D. did D. like of

查看答案

题型：选择题

子宫收缩乏力的常见原因有（）。

A.胎儿先露部下降受阻

B.产妇具有恐惧心理

C.妊娠合并子宫肌瘤

D.产妇过度疲劳

E.胎儿出现急性宫内窘迫

查看答案

题型：选择题

如图所示为一磁流体发电机示意图，A、B是平行正对的金属板，等离子体（电离的气体，由自由电子和阳离子构成，整体呈电中性）从左侧进入，在t时间内有n个自由电子落在B板上，则关于R中的电流大小及方向判断正确的是（　　）

A．I= ，从上向下

B．I= ，从上向下

C．I= ，从下向上

D．I= ，从下向上

查看答案

题型：选择题

属外源性致热原的物质为（）。

A.单核细胞

B.中性粒细胞

C.嗜酸性粒细胞

D.白细胞介素-1

E.抗原抗体复合物

查看答案

题型：选择题

动态扫描的作用是：（）

Ａ.能获得对比剂的时间增强曲线，有助于某些疾病的诊断

Ｂ.提高图像的空间分辨率

Ｃ.提高图像的密度分辨率

Ｄ.减少病人辐射剂量

Ｅ.减少部份容积效应

查看答案

更多题库