平行四边形是（ ）
A．只有一组对边平行的四边形
B．对边分别平行的四边形
C．特殊的长方形
答案：B
在△ABC中，AB=3，BC=7，则AC的长x的取值范围是（ ）．
The （） company has an excellent reputation-which is understandable, since it's been in business for twenty years and has thousands of satisfied customers.
A．upstart
B．senile
C．flourishing
D．fledgling
