题干
.
— Do you know why the teacher asks for me?
— He wants you to _________ your absence(缺席) last night.
— Do you know why the teacher asks for me?
— He wants you to _________ your absence(缺席) last night.
A：account for
B：call for
C：reach for
D：send for
答案(点此获取答案解析）
A
、AlCl3三种溶液分别与等体积等物质和量浓度的AgNO3溶液恰好完全反应，则NaCl、MgCl2、AlCl3三种溶液的物质的量浓度之比是 （ ）