英语疑问1.There's one thousand students in our school,but six[ ]

英语疑问
1.There's one thousand students in our school,but six[ ]them are girls.
a.hundred of b.hundred c.hundreds of
2.In our school we often have 3 meals[ ]day.
a.every b.a
3.I will hire the man[ ]they say is a good man.
a.who b.whom
4.Many[ ]trees were plant.
a.thousands of b.thousand of c.thousand
5.Ahead of me I saw a woman [ ] I thought was my aunt.
a.who b.whom
6.翻译：They stopped working and went to play when they heard the bell ring or rest.
7.It is in 1960[ ]Chinese first put out flag on Mount Qomolargma.(填引导词）
请问答案是哪些,并说明理由
第5中I THOUGHT不是插入语吗？第6句没语病吗？