--- Is there any possible way to help them get rid of such a bad habit?

--- To tell the truth, it’s very hard. But we   on this problem trying to improve the situation.

A．worked

B．had worked

C．are working

D．had been working

属于水平形插花有（）。

A．东方平展型和西方水平型插花

B．对角线型插花

C．S形插

D．新月形插花