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【单选题】
已知化合物A在薄层板上从样品原点迁移7.2cm,样品原点至溶剂前沿14.4cm,求化合物A的比移值是( )
A.
0.65
B.
0.55
C.
0.50
D.
0.45
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【单选题】-- Shall I wait here for three hours? --Yes. Three hours _____ to wait for such a doctor.
A.
was not long enough for you
B.
are not very long for you
C.
is not long enough for you
D.
will be too long for you
【单选题】—Shall we leave for home now? —No, I  ______ here until Tom comes back. [     ]
A.
won’t wait
B.
will leave
C.
will wait
D.
won’t stay
【单选题】 减法电路如图所示,R1 = R2 = R3= Rf,输入u i1 为1V,u i2 为2V,则输出为( )V
A.
1
B.
2
C.
3
D.
0
【单选题】减法电路如图所示,R1 = R2 = R3= Rf,输入u i1 为2V,u i2 为1V,则输出为( )V
A.
-1
B.
1
C.
3
D.
5
【判断题】从西方历史学家的角度看,唐朝比当时任何一个国家都开放,它也因此成为中华文明的象征。 (3 puntos) 答案: Desde el punto de vista de los historiadores occidentales, la dinastía Tang fue más abierta que ninguna otra nación de su época, por lo cual se...
A.
正确
B.
错误
【单选题】Shall I go with you _____ wait here?
A.
and
B.
or
C.
but
【单选题】“锁“在记号中的意思是指
A.
锁头
B.
金锁
C.
锁住
D.
开锁
【单选题】---How long shall we wait here? -The first bus set out earlier than usual today and _______ be here any time, I think.
A.
should
B.
might
C.
can
D.
must
【单选题】------shall I stay here or wait there ? ------________.
A.
It makes no difference
B.
It is no problem
C.
It depends
D.
It's Ok
【单选题】-- Shall I wait here for three hours? --Yes. Three hours ___to wait for such a doctor.
A.
are not very long for you
B.
is not long enough for you
C.
was not long enough for you
D.
will be too long for you
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