液相色谱法分析水中多环芳烃时,萃取液通过净化层析柱应控制流速在()范围内。A.1-2

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问题:

液相色谱法分析水中多环芳烃时,萃取液通过净化层析柱应控制流速在()范围内。

A.1-2ml/min

B.6-8ml/min

C.10-12ml/min

考点:环境科学技术及资源科学技术环境监测环境监测题库
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进口( )货物,收货人应办理审批手续。

A.血液及其制品

B.活动物

C.水果

D.小麦

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A 24-year-old client on the labor unit is being coached in the Lamaze method by her husband. On assessment, the nurse finds the client to be 5 cm dilated, 90% effaced, at +1 station with contractions coming every 2 to 3 minutes and lasting 35 to 40 seconds. The client has asked for pain relief. What’s the nurse’s best action ?()

A.Check maternal blood pressure and pulse and fetal heart rate in response to contractions.

B.Realize that it’s too early to give pain medication, and encourage the husband to continue with the Lamaze coaching.

C.Arrange for a sonogram to determine fetal position.

D.Perform a vaginal examination to determine dilation, effacement, and station.

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骨下袋的特点,除外()。

A.骨下袋的牙槽骨呈垂直或角形吸收

B.骨下袋的牙槽骨可呈水平吸收

C.牙周袋的袋底位于牙槽嵴顶的根方

D.袋壁软组织位于牙根面和牙槽骨之间

E.牙槽骨构成牙周袋壁的一部分

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如图7-47所示为三相异步电动机正反转电路中的控制电路。控制正转和控制反转的支路中分别串接了KM、KMF两个常闭触头,它们所起的作用是()。

 

A.保证两个吸引线圈不发生短路

B.保证两个接触器不同时动作

C.保证主电路交换两相电源线

D.保证两个吸引线圈同时得电吸合

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硬脑膜下血肿患者有典型的中间清醒期。()

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