小题1:He said he would________(推荐) me to Professor Wang as his student. 

小题2:I don’t understand why he refused to________(承认) that he had been defeated. 

小题3:Our country is ________(丰富的；充裕的) in natural resources.

小题4:We           (用... 代替)a red ball for the blue one to see if the baby would notice.

小题5:You must not be          (支配) by what other people say.

小题6:Between 1942 and 1945 more immigrants came to California to work in the ship and a____(飞机) industries.

小题7:Most _____________(申请者) know that they have very little chance of getting a visa to California.

小题8:It became ___________(显而易见的) to everyone that they made a wrong decision.

小题9:The m___________ of the first Spanish were religious men who came to teach the Catholic religion to the natives.

小题10:I think you should make an ________(道歉) to her at once.

某同学用一定质量分数的Na₂CO₃溶液做“Na₂CO₃+CaCl₂=2NaCl+CaCO₃↓”的实验．其五次实验结果如下表所示：

根据实验结果回答下列问题：

(1)哪几次反应碳酸钠有剩余(填序号) ____        _____ ．

(2)表中X的值是 _________ ．

(3)试计算碳酸钠溶液中溶质的质量分数．