非金属密封的公称直径≤50mm的阀门,其强度试验持续时间不得少于( )s。
A.15B.30C.60D.180
参考答案:A
—Well. I do think the rabbit is a beautiful, gentle animal which can run very fast.
—_____________.
A.So it is
B.So is it
C.So does it
D.So it does
广告文案的主题主要由()等因素构成
A.商品特征
B.企业特征
C.语言特征
D.消费者特征