建筑工地常备的消防器材有()。
A.砂子
B.水桶
C.铁锨
D.灭火器
E.水池
参考答案:A, B, C, D
Unrest and violence in North Africa and the Middle East ____ at their fastest rate since 2008. [ ]
A. have been raising
B. have been rising
C. have raised
D. have risen
简述外观设计的特征。