浓密的黑烟正从烟囱中涌出。

___Thick, black smoke was pouring out of the chimney.

楼梯上的烟雾如此浓密，我们看不清下楼的路。

The smoke on the stairs was so ___thick that we couldn't see our way down.

浓雾让人很难看清几英尺以外的东西。

The ___thick fog made it difficult to see more than a few feet ahead.