很难解释清楚什么原因使他如此走红。

It is difficult to define what makes him so popular.

《牛津词典》

阿尔卡特的埃尔文先生说：准确地说很难解释是什么使网络电视那么使人着迷。

Exactly what makes IPTV so compelling is hard to explain, says Alcatel's Mr Alwan.

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但近代哲学狭隘的认识论视野使认识问题成为难解之谜。

But the epistemological problem became a mystery which is not easy to uncover because of the narrow eyesight of the Modern time Philosophy.

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