用30克盐制成含盐30%的盐水，需加水100克．______．
30÷30%-30，
=100-30，
=70（克）；
答：需加水70克；
故答案为：×．
Smartphone ____ people of different ages that it soon becomes popular in the market. [ ]
A. exposes to
B. links to
C. attends to
D. appeals to
停炉后，空预器热端温度多少度以下，可以进行水冲洗？
