Definition: difficult to see through Level: B2
浓密的黑烟从烟囱中涌出。
___Thick, black smoke was pouring out of the chimney.
烟雾如此浓密，以至于我们无法看透。
The smoke was so ___thick that we couldn't see through it.
浓雾使得驾驶变得危险。
The ___thick fog made driving hazardous.
