1.our classroom is ()than theirs.A much brighter B more bright.要说为什么

1.our classroom is ()than theirs.A much brighter B more bright.要说为什么
2.English is one of John's () subiects.A the worst B worst 请问如果将A改成the worst是不是就对了?
3.my best friend often shares things with me and helps people ()trouble.A with B in .请问为什么不能选A?help sb with sth ,
4.he is goot at singing and he does better in singing than anyone else in his class.请问he是和in his class.做比较的.为什么用better 而不用 best?
5.this meeting is more impoutant than that one.请问one为什么不能去掉.
6.this morning Jack came to school () than () students in his class.A much later ,the other B much later any other .要说为什么,另译这个句子.
7.he looked more like a child than a man in his forties.请问这是个副词比较级的句子吗?副词能修饰介词吗?in his forties怎么译?