The school rule states that no child shall be，unless________by an adult，allowed out of the school during the day.

A．was accompanied

B．accompanying

C．accompanied

D．being accompanied

硫酸与皮肤接触时会引起深度、严重、疼痛的（）。

A.中毒

B.神经系统中毒

C.灼伤

D.深度腐蚀