He clammed up when I asked him where he gets his stories .

当我问他是从哪里获得这些资料时，他守口如瓶，不肯透露一点风声。

The pedlar clammed up when I mentioned the police .

我一提到警察小贩就不作声了。

Even some usually voluble critics clammed up tuesday .

甚至是一些通常直言不讳的批评人士周二也三缄其口。

He clammed up over their possible future moves .

对于他们今后可能采取的步骤，他保持缄默。

She clammed up when I mentioned the police .

我一提到警察她就不作声了。