问题 计算题 用简便方法计算。(1)6.25×2.3+3.75×2.3(2)0.8×(12.5+1.25) 答案 (1)6.25×2.3+3.75×2.3 =2.3×(6.25+3.75) =23(2)0.8×(12.5+1.25) =0.8×12.5+0.8×1.25 =11 选择题 The little girl looked at the host with a ____ expression . Maybe the question was quite_____.A puzzled ; puzzled B puzzling ; puzzled C puzzled ; puzzling D puzzling ; puzzling 查看答案 单项选择题 A1/A2型题 酶可作为工具来检测某些血浆成分,这主要是利用酶的哪一个特性()A.极高的催化效率B.高度专一性(特异性)C.高度不稳定性D.反应的可逆性E.不易受到干扰 查看答案