Smell is keener in dogs than in humans.

狗的嗅觉比人的嗅觉灵敏。

The leaders of the Maine towns are keener.

缅因州的领导者更为热心。

Mr Obama plainly has a keener sense than Mr Bush did of American limits.

在对美国局限性的认识方面，奥巴马先生显然要比布什先生敏锐。

The fact that animals have keener senses than humans is well-documented.

动物不见得就比人类更有预测地震海啸的天赋，它们只是感官更加敏锐而已。

"Salmonella doubles every 20 minutes under ideal conditions," Keener said.

基纳说，在理想环境下，沙门氏菌每20分钟复制。