蜂鸟发现花蜜和花粉是很有营养的.Hummingbirds have discovered that nectar and pollen are very nutritious.为什么蜂鸟和大猩猩都有脊骨?Why do hummingbirds and gorillas both have backbones?小蜂鸟栖在山楂树枝上.The hummingbird perches on a twig of the hawthorn....
Add 20 mg. of diatomaceous earth filter aid per liter of solution.对每升溶液加入20毫克硅藻土助滤剂.The bottle holds a liter of beer.这个瓶子装一升啤酒.This bottle holds one liter.这个瓶子装一升....