形容人心难以捉摸，民众的行为像烟一样飘忽不定。

The evidence seems to favor the view that the fundamental structure of the virus is a hollow tube.

The writer must be a person who is willing to fail.

伟大的事情都很简单。而且大多数都可以被凝结成一个简单的单词：自由；公正；荣誉；责任；仁慈；希望。