The boy is very clever .He can work out such a maths problem without d_.

问题描述:

The boy is very clever .He can work out such a maths problem without d_.

difficulty 困难 n.
这个男孩可以毫无困难地解出这种数学题。

ifficulty
同意楼上的观点

difficulty 困难.全句的意思是:这个男孩很聪明,他可以毫无困难地解出这种数学题.