1.This exam is a real c_____.Please study hard for it.2.Most children can not c___ on one thing fo
问题描述：
1.This exam is a real c_____.Please study hard for it.2.Most children can not c___ on one thing fo
1.This exam is a real c_____.Please study hard for it.
2.Most children can not c___ on one thing for a long time.
3.Don't you remember ____(borrow) 100Yuan from me?
答
challenge
这测试是个挑战.
concentrate on
专注于……
borrowing
remember doing=remember having done