皮皮学，免费搜题
登录
搜题
【多选题】
PCR过程中的注意事项包括是。A.
由于PCR灵敏度非常高，所以应当采取措施以防反应混合物受到污染。
B.
操作中所用的PCR管、离心管、吸管头等都只能一次性使用。每加一种反应物，新的枪头。
C.
设置严格的阳性对照和阴性对照。
D.
注意不能有RNA酶的污染。
手机使用
分享
复制链接
新浪微博
分享QQ
微信扫一扫
反馈参考答案：
举一反三
【单选题】Which step is the most important for you to buy a good computer? ______.
A.
The first step.
B.
The last step.
C.
The fifth step.
D.
The second step.
【单选题】According to the passage, the first step helps the readers______.
A.
read first several paragraphs
B.
scan the whole chapter
C.
study the graphs
D.
get the theme of the chapter
【判断题】The first step in the process of error analysis is the identification and description of errors.()
A.
正确
B.
错误
【单选题】—Which coat would you prefer ， sir? —I’ll take ， to have a changesometimes ．
A.
． all them
B.
． themall
C.
． boththem
D.
． themboth
【单选题】There’re too many clothes in the shop. I really can’t decide .
A.
which to buy coat
B.
to buy which coat
C.
which coat should I buy
D.
which coat to buy
【单选题】Which of the following, if presented as the first sentence of a succeeding paragraph, would most logically continue the discussion presented in the passage?
A.
The influence of volcanic eruptions on global weather patterns is almost completely understood at present.
B.
Scientists have only begun to understand, however, the effects of these wavelengths of light on the global environment.
C.
The majority of global cooling effects have thus been attributed to volcanic explosions.
D.
The human warming activities ameliorate by volcanic eruptions include those produced both by heavy industry and agriculture.
E.
The reason that sulfate aerosols take an unusually large time to disperse owes primarily to meteorological factors, including the jet stream.
【简答题】Who was the first man to step on Antarctica? And when?
【简答题】Which color coat does she finally buy?
【多选题】下列叙述中( )是对气相色谱固定液的要求。
A.
热穗定性好，在使用温度下不会发生热解或化学反应
B.
蒸气压低，不会造成固定液易流失现象的发生
C.
对样品具有一定的选择性，这有助于样品的分离
D.
黏度要高，它有助于样品中的被测组分附着在柱上，便于分离
相关题目：
参考解析：
知识点：
题目纠错 0
发布
