The flower bud of a water lily 百合 opens at sunset since .its opening is triggered(commence) .by the decreased light.

Food must be moist in order to have a taste.

With lasers scientists can probe many physical processes, such as combustion, once beyond our ken.视野

Some animals pant and sweat to speed evaporation of body moisture and thus cool themselves.

Double Eagle in the first transatlantic balloon, was greeted by avid crowds in France.

By the nineteenth century, embroidery on men's clothing had virtually disappeared except for the occasional decorative vest and tie.

The Salk vaccine is a major factor in the fight to eradicate polio.

Comets are still regarded with awe by some people.

The economy of Dallas, Texas, is strong and diversified .