Reptiles and birds are divided into two classes, reptilia and aves. give an example of a fossil evidence that would be the best support for this division?

Idon’t know the answer and i’ve been stuck on it for a while now skskskskks

Which of the following is a limitation of a clinical trial? a.)amount of random assignments b.)hospital cost c.)number of test tubes d.)amount of peer review

What part of the cell does 9 represent? a. cytoplasm b. lysosome c. ribosome d. centrosome