变应性鼻炎鼻分泌物涂片检查可见A．较多嗜酸性粒细胞 B．白细胞多见 C．红细胞多见

引进设备材料国内检验费费率一般为( )。

A．1%
B．10%
C．2.3%
D．0.5%

A travel company wants to charter a plane to the Bahamas. Chartering the plane costs $8,000. So far, 18 people have signed up for the trip. If the company charges $300 per ticket, how many more passengers must sign up for the trip before the company can make any profit on the charter ？（）

A. 7

B. 9

C. 13

D. 27

E. 45

装置停车时熄火后循环，（）冷却器必须给上冷却水。

A.煤油

B.柴油

C.馏分油

D.渣油

Stroot效应