[求助]04-7-jj -47 cr

nowandfuture

47.

Whales originaled in freshwater lakes and rivers of ancient asia about 60million years ago。 Not until about 10 million years later did species of whales develop 专门kidneys enabling them to drink salt water. Although fossil evidence shows that some early whale species that lack salt kidney sometimes frequently swam in earth's saltwater oceans, thest species must have to return frequently to freshwater river to drink.

1. fossiles of whale species different from between 60 million and 50 million years ago will not be found to continents that were at times sperated from ancient asia by wide expanse of ocean.

2. among fossiles from later than 55 million ago, none are fossile of whale species sperated the drink only fresh water.

3.Fossiles of whale drank fresh water will not be found in close proximity to fossile of whale speices than drank salt water.

4. between 50 and 60 million years ago, fresh water lake and river on which whale originate were invade gradually by salt water.

nowandfuture

ding ,这句子是什么意思啊