【单选题】【消耗次数：1】
使用液相色谱仪时，样品溶液是否需要过滤？（ ）
①
A、是的，必须过滤
②
B、不需要过滤
③
C、根据样品类型决定
④
D、只在高浓度时需要过滤
参考答案：
复制
纠错
相关题目
【多选题】
使用气相色谱仪进行样品分析时，以下哪些操作是正确的？（ ）
①
A、确保载气瓶中的气体充足
②
B、使用前检查气体泄漏
③
C、不需要预热就直接进样
④
D、使用后关闭气体阀门
随机题目
【多选题】
_____________ , he began to write a report.
①
Finish the exploration
②
Having finished the exploration
③
The exploration finished
④
The exploration finish
【单选题】
The government enacted new laws to ________________ terrorism(恐怖主义).
①
fight for
②
fight against
③
fight in
④
fight at
【单选题】
Anger is a normal emotion that we all feel from time to time. Some people express anger openly in a calm reasonable way. Some explode with anger, and scream and shout. But other people keep their anger inside. They can not or will not express it. This is called repressing anger. Many doctors think that repressing anger is more dangerous to a person’s health than expressing it. They say that when a person is angry, the brain gives out the same hormones (荷尔蒙) as that are produced during tense and nervous situations. They speed the heart rate and raise blood pressure, so the person feels excited and ready to act. Repressing these feelings will only make the feelings continue, and this can lead to many medical problems. To prevent these problems, these doctors suggest letting the anger out by expressing it freely. But recently some other doctors question this. They say that people who express anger repeatedly and violently become, in fact, more but not less angry. And this could cause medical problems. However, some doctors say that both repressing and expressing anger can be dangerous. They believe that those who express anger strongly may be more likely to develop heart diseases, and that those who keep their anger inside may face a greater danger of high blood pressure. Doctors say the solution is to learn how to deal with anger. The first step is to admit that you are angry and to recognize the real cause of the anger, and then to decide if the cause is serious enough to get angry about. If it is, do not express your anger while angry. Wait until your anger has cooled down, and express yourself calmly and reasonably. Doctors also say that a good way to deal with anger is to find humor in the situation that has made you angry, for laughter is much healthier than anger.What is the main idea of this passage?
①
Anger should be dealt with in a proper way.
②
Different people deal with anger in different ways.
③
Doctors suggest dealing with anger by repressing it.
④
The best way to deal with anger is to laugh when angry.
【单选题】
It is _____________ that today people in some remote areas know about the rest of the world.
①
difficult
②
amazing
③
inferior
④
superior
【单选题】
They dont____________ the importance of this problem.
①
understands
②
understood
③
understanding
④
understand
【单选题】
The people who ____________ cars work very quickly.
①
astonish
②
assemble
③
afford
④
acquire
【单选题】
Tommy: Mommy, when will we have dinner? I’m starving.Mother: __________ We have to wait for Daddy.
①
OK, honey.
②
Quickly, honey.
③
Soon, honey.
④
All right, honey.
【单选题】
He____________ cold and hunger a great deal.
①
escaped from
②
suffered from
③
kept away from
④
came from
【单选题】
Youdonthavetobeinsuchahurry,Iwouldratheryou________onbusinessfirst.
①
wouldgo
②
willgo
③
went
④
havegone