试题与答案

实验室不用电解水制取氧气的原因是( ) A.装置复杂,制取不便 B.药品昂贵,成

题型:选择题

题目:

实验室不用电解水制取氧气的原因是(  )

A.装置复杂,制取不便

B.药品昂贵,成本太高

C.收集困难,不易验证

D.条件太高,不易达到

答案:

答案:A

通过分析电解水实验可知道,电解水用的是蒸馏水(加入少量硫酸或是氢氧化钠增强导电性)药品价格不高,B错;用水电解器或是简易装置电解水收集都不是一个大问题,尤其是氧气不易溶于水直接收集即可,C错;电解水使用直流电源,一般在物理实验室都有学生电源可以直接变换交流电为直流电,D错;电解水使用的是水电解器或是简易装置,不好携带使用不便,故A正确。

试题推荐
题型:句型转换

句型转换。

1. However you look at it, it's going to cost a lot. (同义句)

    ____ _____ _____ you look at it, it's going to cost a lot.

2. He asked me to get on his car when I was walking on a lonely street.  (同义句)

    He ____ me ____ ____ when I was walking on a lonely street.

3. Do you know when we will visit the Great Wall?  (同义句)

    Do you know when ____ ____ the Great Wall?

4. The firm has offered a good car for me.  (同义句)

    The firm has ____ me ____ a good car.

5. I would like to have a cup of coffee.  (同义句)

    I ____ ____ having a cup of coffee.

6. "Will you go to the cinema tomorrow?" she asked me. (间接引语)

    She asked me ____ I ____ go to the cinema the next day.

7. Could you tell me how to get to the post office?  (同义句)

    Could you tell me ____ ____ ____ the post office?

8. The boy looks like his brother.  (同义句)

    The boy ____ ____ ____ his brother.

9. She was seen to come out of the library by him. (主动语态)

    He ____ ____ ____ out of the library.

10. I think the most helpful invention is the light bulb. (对划线部分提问)

      ____ do you think ___ the most helpful invention?

查看答案
题型:阅读理解与欣赏

古诗鉴赏。

(1)杜甫的《望岳》一诗中的千古名句是                                   ,                                     。

(2)这两句诗集中表现了青年杜甫怎样的思想感情? 

                                                                                                                                                               

查看答案
题型:单项选择题 案例分析题

患者女,34岁,1年前发现右乳肿物,在当地诊为“纤维腺瘤”,近1个月增大迅速。触诊:右乳外上象限肿物,质硬,边界尚清,活动可,右腋下可及2枚淋巴结,有融合,较大者直径为2cm。钼靶X线征象:右侧乳腺直径2cm高密度影,可见砂砾样钙化,BI-RADS5级。右乳肿物粗针穿刺示浸润性乳腺癌,非特殊型,Ⅲ级8分,ER阴性,PR阴性,HER2(+++)。右腋窝淋巴结细针穿刺可见癌细胞。

该患者的最佳综合治疗方法为()

A.先手术,后化疗

B.先行新辅助化疗,再手术

C.先行新辅助化疗联合曲妥珠单抗治疗,再手术

D.先行新辅助化疗联合曲妥珠单抗治疗,再手术,继续完成化疗后行放疗

E.先行新辅助化疗联合曲妥珠单抗治疗,再手术,继续完成化疗后行放疗,之后辅以内分泌治疗

查看答案
微信公众账号搜索答案