问题
You must concentrate more ______ your English study. [ ]
A: to
B: in
C: on
D:at
B: in
C: on
D:at
正确答案是：
同类题型
I’m very glad I have my own room in my house. I ____ do all I like in it.
Did your boss phone you again the next day?—No,it was a fortnight he gave me a second call.
We’ll have a meeting to discuss it _____ the morning of May 15th .[ ]
The old man could cross the busy street _____ the help of his dog. [ ]