为了除去MgCl2溶液中的Fe3+,可在加热搅拌的条件下加入的一种试剂是
A:NaOH
B:Na2CO3
C:氨水
D:MgO
句子配对。
①How heavy is Tom?____ A. There are 15.
②How old is he?____B. He is 15years old.
③How much is the robot?____C. He weighs 51kg.
④How many boys are there under the tree?____D. It's September 15th.
⑤When is your birthday?____E. It's ¥15.
下列命题正确的是( )