数量成熟
参考答案：
林分生长发育过程中材积平均生长量达到最大时的状态称为数量成熟，此刻的年龄称为数量成熟龄。
_____ you didn’t know the rules won’t be an excuse for your failure to report.
A．That
B．What
C．Because
D．How
— Why did you leave without a word of warning to John?
— But what _____ otherwise? He never likes to listen to me.
A. could I do
B. could I have done
C. must I have done
D. should I do
