By accident, he _______he had done something wrong and that he hadn’t been prison for a few weeks.

A．let out

B．made out

C．made sure

D．took care

铸造时石膏类包埋材料的加热温度必须在

A．500℃以下

B．600℃以下

C．700℃2以下

D．1 000℃以下

E．1 200℃以下