His mother wants him _____ at home today. [ ]
A. stays
B. stayed
C. to stay
D. staying
答案:C
女性,18岁。自幼就有轻伤后出血不止。该患者的诊断可能是()
A.肝炎
B.原发性血小板减少性紫癜
C.过敏性紫癜
D.血友病
E.肾炎
下列有关物质用途说法中,正确的是 ①用稀硫酸清除钢铁表面的铁锈 ②用碳酸氢钠作焙制糕点的发酵粉 ③用氢氧化钠中和胃中过多盐酸 ④用熟石灰中和硫酸工厂的污水 [ ]
A.①②④
B.①②③
C.②③④
D.①②③④