叶片受沙尘、油污等污染会改变叶片的（），影响风机的功率。
参考答案：空气动力特性
Google launched its indoor maps feature in Singapore on Tuesday, ______ the city state the second country in Asia to have it.
A．to make
B．make
C．making
D．having made
治疗月经过少痰湿证，应首选（）
A．血府逐瘀汤
B．启宫丸
C．桃红四物汤
D．乌药汤
E．苍附导痰丸
