________work has been done to solve the problem.
举一反三
- __________, the quality has been improved.( ) A: The problem solves B: The problem solved C: The problem to solve D: The problem solving
- ____ work has been done to improve the people’s living standard.
- What can be done to solve the current problem?
- A solution paper is intended to persuade readers to take actions to solve the problem that has been affecting the life of a community.
- ________ research has been done into this difficult and complicated case, so we believe someday we can solve it.