Ｉｆ ｙｏｕ ｗａｎｔ ｓｅｅ ｍｅ ｎａｋ!ｅｄ

Ｉ'ｍ ｏｎｌ!ｉｎｅ:
ｂｒａｉｎｌｙ.ｔｏｄａｙ

Which group of chordates does  notpossess true backbones?                 a.  birds      b.  frogs and toads      c.  lampreys      d.  crocodilians

What will happen to a population of predators if there is a sudden, temporary increase in the number of prey? a. the population of predators will be uniform with no change. b. the population of predators will increase first and then decrease slowly. c. the population of predators will increase continuously.

The circles, or orbits, for electrons are called energy levels. each level can hold only a certain number of electrons. add electrons to each level until you can't add any more. how many electrons can each level hold?