气缸盖安装后试车时发现密封圈秘漏气，原因分析中不正确的是（） A.密封平面不洁夹有异

发布时间：2020-12-11 17:37 │ 来源：www.tikuol.com

题型：单项选择题

问题：

气缸盖安装后试车时发现密封圈秘漏气，原因分析中不正确的是（）

A.密封平面不洁夹有异物

B.缸盖螺母上紧不足或上紧不均

C.最高爆发压过高

D.气缸盖发生了变形

考点：内河船员考试主推进动力装置主推进动力装置题库

题型：单项选择题

阅读理解.根据材料内容,选择最佳选项

Here are five points you can follow to improve your English, and the first point is the most important.

It's your duty to achieve your aims (目标)!
Studying English is your own duty and not the duty of your teacher or your parents. You must take an
active part in your clsses!

Get a teacher or attend a class!
It's a little difficult to study English alone. Also, it's difficult to learn how to speak English if you don't have an English teacher to talk with.

Work as hard as possible in class!
You need to practice speaking often. You should do all of your homework, reading and vocabulary
study outside class and then check the homework in class.

Keep studying!
Don't stop for a long time such as during a summer holiday! To make good progress, you should study at least 5 hours each week.

                                        Make English your hobby and have fun!
    You can improve your English through other activities:
    Reading - choose English books that you can read.
    English songs - choose your favorite English songs and sing them again and again.
    DVDs - many films are also in English with subtitles in your language.
    Travel - traveling in English-speaking countries can help you with your English.

1. Point _____ is more important than any other point.

A. No. 1
B. No. 2
C. No. 4
D. No. 5

2. According to the passage, an English learner should study _____ every week to make good progress.

A. about two hours
B. at least four hours
C. at least five hours
D. more than seven hours

3. The underlined word "subtitles" means "_____" in Chinese.

A. 情节
B. 字幕
C. 画面
D. 人物

4. Which of the following activities is NOT mentioned (提到)?

A. Reading English books.
B. Singing English songs.
C. Watching English films.
D. Writing e-mails in English.

5. The reading above is mainly about _____.

A. how to improve your English
B. why we need to learn English
C. how to study English for pleasure
D. how we can sing English songs well

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题型：单项选择题

神经型食物中毒的病因是（）

A.肉毒杆菌通过血液循环，直接进入中枢神经系统

B.肉毒杆菌产生内毒素引起中毒症状

C.肉毒杆菌产生外毒素抑制神经传导介质的释放，出现软瘫

D.肉毒杆菌产生外毒素作用于脊髓前角，使之功能丧失，出现软瘫

E.肉毒杆菌作用于大脑皮质运动区，出现瘫痪

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题型：单项选择题

下图表示800℃时，A、B、C三种气体物质的浓度随时间变化的情况，t是达到平衡状态的时间。试回答：

（1）该反应的反应物是______。

（2）该反应的化学方程式为__________。

（3）达到平衡状态的所需时间是2min，A物质的平均反应速率为_______。

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在其他条件不变的情况下，扩大样本容量可以（）。

A.降低总体方差

B.降低抽样误差

C.提高估计的精确性

D.提高区间估计的概率保证程度

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题型：单项选择题

ZJl7卷接机组非PLC型显示报告中的132报表为（）报告。

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