为除去食盐中混有的少量CaCl2、MgSO4杂质，小伟设计了一种制备精盐的实验方案，步骤如下（用于沉淀反应的试剂稍过量）：
(1)操作①为________，
(2)操作②④加入的试剂依次为_________ 、__________ ；
(3)操作⑥中加入适量盐酸的作用是___________ ；
(4)操作⑦为_______________ 。
(1)加水溶解
(2)BaCl2 ；Na2CO3
(3)除去过量的碱和Na2CO3，调节溶液的pH至中性
(4)蒸发（或蒸发结晶）
| 完形填空：阅读下面短文，掌握其大意，然后从各小题所给的四个选项中选出最佳选项。 | ||||
| "I am going on a trip" is a word game. Follow these steps to 1 the "I am going on a trip" game:Firstly, have one person 2 by saying that he is going on a trip to a place. He will take with him something that starts with the 3 letter as the place.Example: I am going to Paris and I am taking a poodle (长卷毛狗). Secondly, have the other 4 take turns adding to the list ofthat thing. It must be 5 else that starts with that letter 6 : I am going to Paris and I am taking a poodle and a pen. Thirdly, continue (继续) the game 7 someone is unable (不能的)to think of a word or makes a mistake. Results: That 8 then drops out of the game. Fourth, continue until only 9 person is left after everyone else has dropped out. Results: That person is the 10 . Do you get it? | ||||
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