单项选择题塔下封头材料为低合金钢或高合金钢,在裙座顶部应增设与封头材料相同的短节,通常短节长度可定为保温层温度的4倍,且不小于500mm。 A、正确 B、错误
单项选择题What caused this type of marriage? A. A massive financial burden. B. An expensive dowry. C. The fast-paced life style. D. The aggressive parents-in-law.