According to the fossil record, how long did the transition from fully terrestrial to fully aquatic whales take?

To maintain asepsis when administering an injection, all parts of the syringe can be handled except the:

Nh3 +02-no + h20 is unbalanced what is the balanced equation

Each member of a class sampled a piece of ptc testing paper. thirty people sampled the chemical. twenty persons were tasters. how many had heterozygous genes? 10 20 0-20 indeterminate