曾引起公害病的环境因子主要是
A．氟化物B．甲基汞C．甲醛D．砷化物E．非电离辐射
参考答案：B
—Has the little boy passed P. E. test？
—He has tried twice and the teacher will allow him to have third try.
A．the；不填
B．a； the
C．the； a
D．the； the
The book was written in _______ easy English _______ even primary school students could understand it.
A．so, that
B．such, that
C．too, to
D．enough, to
