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问题 选择题
下列等式中成立的是（　　）
A．
ax
bx
=
a
b
B．-
a-b
c
=
-a-b
c
C．
x2
y2
=
x
y
D．
a
b
=
a-1
b-1
答案

A、

ax
bx
=
a
b
，可见分子、分母有相同的因式x，能约分x，故本选项正确；

B、-

a-b
c
=
b-a
c
，故本选项错误；

C、

x2
y2
=
x
y
，可见分子、分母没有相同的因式，不能进行约分，故本选项错误；

D、

a
b
≠
a-1
b-1
，故本选项错误；

故选A．

单项选择题

具备化学发光免疫分析的最重要的条件是

A．反应过程中必须保证产生足够的激发能

B．反应过程中必须保证信号接受的灵敏度

C．反应过程中必须保证有发光物质对光的吸收

D．反应过程中必须保证有发光物质对光的发射

E．反应过程中必须保证产生足够的光量子
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完形填空

笫二节：根据对话内容，从对话后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

---When is your vocation going to start?

---I'll be leaving on the fifth of August

---    61     How many weeks are you going to be taking?

---I'm taking two weeks now, but l want to save the other week and take ---it sometime during winter.

---That sounds good. 62

---To the beach.

---Have you made your hotel reservation yet?

----  63  I'll be staying with friends.

---You're lucky.     64   

---What about you? When are you planning to take your vocation?

---_  65     I should be thinking about it, I guess.

A． Oh, I don't need to do that.

B．No, not really !

C． That's only a few days from now

D．It’s hard to frnd a hotel in August.E.  That depends. F.  I don't know.

G.  Where are you going?
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