A:Al3+、Na+、NO3-、Cl-
B:K+、Na+、Cl-、NO3-
C:K+、Na+、Cl-、AlO2-
D:K+、NH4+、SO42-、NO3-
(Ⅰ)求集合A;
(Ⅱ)若A∩B=A,求实数a的取值范围.
将下列内容与对应的图片匹配。
( 1 )reading a book ____
A.
( 2 )eating lunch ____
B.
( 3 )listening to music ____
C.
( 4 )drawing a picture ____
D.
( 5 )doing morning exercises ____
E.