问题

Maths ________ not easy to learn
A:concerning
B:until
C:unless
D:provided
B:until
C:unless
D:provided
正确答案是:
同类题型
You look well . The air and the sea foods in Sanya must _____ you , I suppose.
I was close to being killed the other dayA car passed me at______ I thought was a dangerous speed
We congratulated Jerry ____ the championship
The Japanese sufferingfrom the worst natural disasters
On Christmas Eve, we put up some balloons to _______ the festival atmosphere.