The radius of the four circles is one in the figure，then the area of the shade part is________
（英汉小字典：radius：半径；shade：阴影）．

The original railway from A to B is 310km，and now a 280km long high-speed railway is built．The train speed on the high-speed railway is twice the original speed，so the traveling time from A to B is 2 hours shorter．Then the original train speed on the original railway is________km/hour．

The number of intersection point of the graphs of function and function y=kx（k≠0）is

1. A.
   0
2. B.
   1
3. C.
   2
4. D.
   0 or 2

The number of integer solutions for the syetem of inequalities about x is just 6，then the range of value for real number a is
（integersolutions整数解；syetem of inequalities不等式组；the range of value取值范围）

1. A.
   -2.5＜a≤-2
2. B.
   -2.5≤a≤-2
3. C.
   -5＜a≤-4
4. D.
   -5≤a≤-4

The value of （4-3）×2 is

1. A.
   -2
2. B.
   2
3. C.
   1
4. D.
   3

The bigest number in the set{3.2，2.3，3，2.23}is　

1. A.
   3.2
2. B.
   2.3
3. C.
   3
4. D.
   2.23

The sum of all such integers x that satisfy inequality 2≤|2x-1|≤6 is
（英汉词典：sum和．integer整数．satisfy满足．inequality不等式）

1. A.
   8
2. B.
   5
3. C.
   2
4. D.
   0