原文已被隐藏，你可用 快捷键 - 或点击 显示原文 按钮来查看原文
第1段
1 .<-NARRATOR:-> Now listen to part of a lecture on this topic in a biology class.
该句暂无译文！
第2段
1 .<-MALE PROFESSOR:-> So, here's a good example of this.
该句暂无译文！
2 .Mites are very small insect-like creatures.
该句暂无译文！
3 .Mites live in tropical climates and feed on nectar and pollen in flowers.
该句暂无译文！
4 .But these tropical flowers don't last long,
该句暂无译文！
5 .they wilt and fall off quickly, and so the mites need to find new flowers in order to get more nectar and pollen to eat.
该句暂无译文！
第3段
1 .But the mites can't fly,
该句暂无译文！
2 .and they are so small
该句暂无译文！
3 .that it'd take them a while and a lot of effort to climb down one flower,
该句暂无译文！
4 .crawl to another one,
该句暂无译文！
5 .and climb all the way up again.
该句暂无译文！
6 .So how do they get to the next flower?
该句暂无译文！
7 .Well, there's a bird,
该句暂无译文！
8 .the hummingbird... hummingbirds eat the nectar from the same flowers as the mites.
该句暂无译文！
9 .So when a hummingbird comes around and sticks its beak into the flowers to get the nectar out . . .
该句暂无译文！
10 .the mites quickly climb onto the hummingbird.
该句暂无译文！
第4段
1 .Well, as I mentioned, mites are pretty tiny,
该句暂无译文！
2 .so the hummingbird isn't harmed in any way.
该句暂无译文！
3 .And all they do is stick to the hummingbird.
该句暂无译文！
4 .Since the hummingbird also goes from flower to flower for nectar, it takes the mites along.
该句暂无译文！
5 .Once the hummingbird gets to the next flower,
该句暂无译文！
6 .the mites climb off and eat some pollen and nectar there...
该句暂无译文！
7 .on the new flower. Without the hummingbird carrying them from one flower to another,
该句暂无译文！
8 .the mites would find it much more difficult getting food.
该句暂无译文！