某梁的长度为16m,其上部通长筋(HRB335级,直径30mm),应至少计()接头。 ["1个","2个","3个","4个"]
进行ZD1839和安慰剂对照研究的临床试验是()。 ["INTACT","ISEL","BR21","IDEAL","HERA"]
进行ZD1839不同剂量疗效和安全性研究的临床试验是()。 ["INTACT","ISEL","BR21","IDEAL","HERA"]
桃小食心虫和梨小食心虫幼虫最明显的区别在:() ["体色不同","体长","桃小无臀栉而梨小有4-7个臀栉","其它特征"]
炒牛奶要掌握哪人要领?
水对人体有哪些生理功能?