Many students asked the teacher ----- the time of the test.

Many students asked the teacher (C) the time of the test.
A for     B to       C about
许多学生问老师考试的时间,about是”关于“的意思,ask for是”要求（某物）“,ask sb.to do sth.则是要求某人做某事
Of the two T-shirts,the boy chose (C) one.
A more expensive 
 B much expensive
C the more expensive
D the most expensive
两件T恤,要用比较级,特指”更贵“的那一件,所以要加the
(B) of her parents is going to the meeting in the school.
A Both
B Either
C All
D Any 
谓语用is,排除both 和all,any of 后面要加the,所以也不行,either 是”两者中任一“的意思,全句意思就是“她父母中的一个将去学校”