Which period had a special explosion of life forms? Cambrian
O Precambrian
0 248 million years ago
O both A and B

When the oxygen produced by photosynthetic plants in the water dissolves in the water, which of these is being formed?

Fill in the blank with the best word to complete the sentence. white blood cells protect against and aid in blood clotting when injuries are sustained.

Ascientist is designing an investigation to study the impact of invasive bird populations on local, native bird populations at backyard bird feeders. what population is most likely to be a control group for the investigation? amount of food number of bird feeders invasive bird populations local backyard birdfeeders without food