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举一反三
【单选题】下列关于浸渍法特点的陈述，错误的是
A.
浸渍时溶剂是相对静止的
B.
浸渍法的浸提效率较渗漉法低
C.
适于遇热易破坏和易挥发成分的提取
D.
当溶剂的量一定时，浸提效果与浸提次数无关
E.
与浸渍的时间有关
【单选题】How should one invest a sum of money in these days of inflation (通货膨胀) Left in a bank it will hardly keep its value, however high the interest rate is. Only a brave man, or a very rich one, dares to b...
A.
suggest human beings are controlled by a clock
B.
describe why clocks can rule the planet Earth
C.
tell readers what clocks look like
D.
compare clicks to human beings
【单选题】关于压缩空气起动的正确论述 。 I.起动空气应有足够压力和一定储量 II.起动空气必须在膨胀行程中进入气缸 III.四冲程柴油机起动最少有4个气缸 IV.二冲程进气延续角约为100°曲轴转角 V.达到起动转速后柴油机才能发火起动 VI.二冲程柴油机起动最少有六个气缸
A.
Ⅰ+Ⅱ+Ⅲ+Ⅳ
B.
Ⅰ+Ⅱ+Ⅳ+Ⅴ
C.
Ⅱ+Ⅲ+Ⅳ+Ⅴ
D.
Ⅱ+Ⅳ+Ⅴ+Ⅵ