“May I go and play with Dick this afternoon, Mum?” “No, you can’t go out _______ your work is being done.”

A．before

B．until

C．as

D．the moment

填塞塑料最佳的时期是

A．粥状期
B．丝状期
C．橡皮期
D．硬化期
E．以上都不是