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【单选题】
采用酶抑制率法快速检测蔬菜中有机磷和氨基甲酸酯类农药残留时,当蔬菜样品中提取液对酶的抑制率≥()时,表示蔬菜中有高剂量有机磷或氨基甲酸酯类农药存在。A.
20
B.
30
C.
50
D.
60
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【单选题】--- Must we go there together? ---______ you ________ he goes there, only one student is needed.
A.
Both; and
B.
Either; or
C.
Neither; nor
【单选题】We are a team so we must assist one another _____ completing the task．
A.
with
B.
to
C.
at
D.
in
【单选题】测定胎儿、胎盘功能最常用的方法是
A.
测定尿中雌三醇值
B.
测定尿中雌激素/肌酐比值
C.
测定尿中绒毛膜促性腺激素
D.
测定尿中胎盘生乳素
E.
测定血液中胎盘生乳素
【单选题】Every one of us must know：________we live can we save the earth.
A.
by changing the way only
B.
only by changing the way
C.
by only changing the way
D.
by changing only the way
【单选题】昨天我试验人员在混凝土力学室(温度18°C)对一组标准试件(150×150×150mm)进行试验,其试件破坏荷载分别为625.8KN、603.5 KN、504.0 KN,请确定该组混凝土立方体抗压强度值为:()
A.
26.8 Mpa
B.
27.3 MPa
C.
25.4 Mpa
D.
试验结果无效
【单选题】听力原文： We must admit that their job is not the most romantic one in the world. We often take dustmen for granted. Perhaps because they usually come very early in the morning, before most people are up,...
A.
Because they are often early risers.
B.
Because they often do their work unnoticed.
C.
Because they were born to do their work.
D.
Because people never stop to talk to them.
【简答题】一组6块石灰岩石料的饱水单轴抗压强度试验结果分别为：214.5kN、215.6kN、 195.2kN、197.5kN、199.4kN、205.0kN，试件采用边长为50mm的标准立方体试件。试计算试验结果，并分析该石灰岩能否用于配制C30的水泥混凝土?
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