Our teacher told us last night that ___.

A．English is difficult to be learnt

B．the English is difficult to learn

C．the English language is difficult to learn

D．English language is difficult to learn

人为因素引起的火灾主要表现在（）。

A.用火不慎引起火灾

B.不安全吸烟引起火灾

C.人为纵火

D.机械撞击损坏线路导致漏电起火

E.使用电加热装置时，不慎放入高温时易爆物品导致爆炸起火