A:①②④
B:①②③
C:②③④
D:①②③④
a、b两物质的溶解度曲线如图,在t3℃时,把a、b两物质各5g分别加入到50g水中,则下列说法正确的是( )
8+____=15
3+____=11
(2015•广东佛山)________ I live in a safe community, I still feel a little worried when I go out at night.