比较级： more closely
最高级： most closely

The two features are closely related .

这两个特征密切相关。

The times is watching twitter closely .

《纽约时报》一直在密切关注twitter。

Economic and financial policies must be co-ordinated more closely .

经济和金融政策必须更加紧密地协调起来。

Since 1945 , it has stuck closely to america .

而1945年以来，则一直紧紧粘着美国。

But look more closely and two things are clear .

但更仔细地考虑一下，这两件事情是显而易见的。