题目

-Mrs. Lin is going to see his son in the UK without telling him.         -Really? That'll give him a big           .          A.kiss    B.chance    C.gift   D.surprise 答案：D用氢、氧、碳、钙四种元素中的一种或多种组成符合下列要求的物质，分别写出相应的符号或化学式．（1）2个氢原子 ；     （2）一种阴离子 ；（3）一种氧化物 ；  （4）一种碱 ．