In view of all sorts of rumors and guesses, experts carried out some careful and scientific research and         the possibility of a second earthquake in this area.

A．blamed

B．discounted

C．attended

D．charged

用靛蓝二磺酸钠分光光度法测定空气中臭氧的浓度时，空气中主要干扰物质是（）。

A.二氧化碳

B.一氧化碳

C.二氧化硫

D.甲醛

E.苯