更换瓶阀或密封材料时必须符合()的规定。
A.GB7512
B.GB7612
C.GB7511
D.GB8512
参考答案:A
“Are you satisfied with his answer?” “Not at all. It couldn’t have been ____.”
A.better
B.worse
C.more
D.less
简述莎士比亚喜剧的特点。