题目

根据图片完成句子 （1） On , Mary has a school trip. （2） On , Jim has an English test. （3） On , Sally has a book sale in the school. （4） On , Bob has a basketball game. （5） On , I have a birthday party. 答案：【1】Monday 【1】Tuesday 【1】Wednesday 【1】Thursday 【1】Friday用适当的符号和数字填空：①2个铁离子2Fe3+2Fe3+； ②3个氨分子3NH33NH3；③氢氧根离子OH-OH-．