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问题 解答题
计算
（1）(-
1
2
)-1-23×0.125+(
3-27
-2012)0
（2）(
-a
b
)2÷(
2a2
5b
)2•
a
5b

（3）
m+2n
n-m
+
n
m-n
-
2n
n-m

（4）(
x
x-y
-
2y
x-y
)•
xy
x-2y
÷(
1
x
+
1
y
)．
答案

（1）原式=-2+8×0.125+1

=-2+1+1

=0；

（2）原式=

a2
b2
÷
4a4
25b2
•
a
5b

=

a2
b2
•
25b2
4a2
•
a
5b

=

5a
4b
；

（3）原式=

m+2n
n-m
-
n
n-m
-
2n
n-m

=

m+2n-n-2n
n-m

=

m-n
n-m

=-1；

（4）原式=

x-2y
x-y
•
xy
x-2y
÷
x+y
xy

=

x-2y
x-y
•
xy
x-2y
•
xy
x+y

=

x2y2
x2-y2
．

单项选择题

两侧唾液腺摄取低下常见于（）。

A.病毒感染

B.细菌感染

C.干燥综合征

D.放射性炎症

E.酒精中毒
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句型转换

1. My grandfather left his hometown over 55 years ago.

My grandfather　_______________________________ for ____________ 55 years.

2. My grandparents got married 50 years ago.

It’s 50 years________________________________________________

3. My grandfather arrived in Nanjing last Monday. He is still in Nanjing.

My grandfather has　___________________ since last Monday.

4. My grandfather went to bed very late last night. He was too excited.

My grandfather_________________ go to bed__________ it was very late last night. He was too excited.

5. It took my grandfather two days to travel around the center of the city.

My grandfather　______________ two days______________________ the center of the city.
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