詞匯

1.?????????????multiple?多種的

2.?????????????encounter?遇到，遭到

3.?????????????estimate?估計

4.?????????????increase?增加

5.?????????????resistance?阻力

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A dolphin superpod

Dolphins often travel in groups called pods. Most pods are made up of two to 30 dolphins that hunt, mate and raise their young together. When multiple pods join together, they create superpods of hundreds or even thousands of dolphins.?

A lucky tour group encountered a superpod off the coast of Newport Beach, California. The group was estimated to contain as many as 2,000 common dolphins.?

Some scientists think dolphins increase their speed by jumping since there is less resistance in the air than in water.