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【简答题】
--- I have just had my watch repaired. --- How much did they         for that? A. cost           B. charge        C. spend           D. take
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参考答案:
举一反三
【单选题】克莱门森(Clemmensen)还原反应,所用催化剂是
A.
LiAlH4
B.
AlCl3
C.
NaBH4
D.
Zn-Hg
【单选题】It is very kind of you to me at the airport.
A.
see off
B.
meet with
C.
see through
D.
see to
【单选题】克莱门森(Clemmensen)还原反应,所用催化剂是( )
A.
NaBH4
B.
LiAlH4
C.
Zn-Hg
D.
AlCl3
【简答题】At first sight the planet Mars(火星)does not appear very welcoming to any kind of life. It has very little oxygen and water, the temperature at night is below 50 degrees and winds of 100 miles(161 kilom...
【单选题】At the first sight the planet Mars(火星)does not appear very welcome to any kind of life. It has very little oxygen and water, the temperature at night is below -50°C and winds of 100 miles per hour cau...
A.
there is no life there now
B.
there is a large amount of water at the poles
C.
the Mars may be able to support life in the future
D.
conditions may have been similar to those on the Earth
【单选题】以下哪个选项描述了克莱门森(Clemmensen)反应?( )
A.
无α-H的芳香醛与具有α—H的脂肪族醛酮进行交叉缩合反应脱水形成α,β-不饱和醛、酮的反应
B.
羰基在锌汞齐浓盐酸作用下,被还原为亚甲基的反应
C.
将醛、酮和肼反应生成腙,再与金属钠或钾在封管或高压釜中加热至较高温度后,把羰基还原为亚甲基的反应
D.
无α-H的醛在浓碱条件下,一分子的醛氧化为羧酸盐,另一分子的醛还原为醇的反应
【单选题】At the first sight the planet Mars does not appear very welcome to any kind of life. It has very little oxygen and water; the temperature at night is below -50℃ and winds of 100 miles per hour cause s...
A.
there is no life there now
B.
there is a large amount of water at the poles
C.
the Mars may be able to support life in the future
D.
conditions may have been similar to those on the Earth
【判断题】尿酸能提高人体的氧化反应效率。
A.
正确
B.
错误
【单选题】学生在校期间,不得打架斗殴,对打架事件责任者,下列处理中不正确的是( )。
A.
因不守秩序,不听劝告,用语言侮辱或其它方式触及他人,引起事端或激化矛盾,虽未动手打人,但造成后果者,给予警告分
B.
持械打人或勾结校内外人员聚众打架,给予留校察看或开除学籍处分
C.
以劝架为名,偏袒一方,促使事态扩大,产生严重后果者,视情节给予记过、留校察看或开除学籍处分
D.
参与打架三次以上者,不论情节如何一律给予开除学籍处分
【简答题】Yoga(瑜伽) is a kind of sport.It is very 46 around the world now. Every one can do yoga. It’s good 47 men and women. 48 do people like yoga? It’s 49 to say.. The short answer is that yoga helps you to 5...
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