Given in the △ABC ，a，b，c are three sides of the triangle，and，then ∠A is

A．acute angle                     B．right angle  

Given in the △ABC,a,b,c are three sides of the triangle, a=3, b=10 and perimeter of the triangle is multiple of 5, then the length of c is            。

（英汉小词典：side：边；perimeter：周长；multiple：倍数）

Root of the equation is         ．

(英汉小字典：root根；equation方程．)

Assume that the reciprocal of m+2 is ，them the value of is ________．
（英汉词典：to assume假设；reciprocal倒数；value值）

Root of the equationis ________．

Digits of the product of 25¹⁷×2³³is
（英汉小词典：digits位数，product乘积）

1. A.
   32
2. B.
   34
3. C.
   36
4. D.
   38

As in the figure，there are four circle with radius of 2．The four circles are apart from each other．Link their centers to form a quadrilateral，then the total area of the shaded parts in the figure is

1. A.
   2π
2. B.
   4π
3. C.
   6π
4. D.
   8π