那只大狗在陌生人靠近时发出低沉的咆哮声。

The big dog started to ___growl when the stranger came too close.

“离我远点！”他对那个陌生人怒喝道。

"Stay away from me!" he ___growled at the stranger.

当摩托车启动时，引擎发出低沉的轰鸣声。

The motorcycle's engine ___growled deeply when it started.