Answer & explanation:
The cell was discovered in 1669 by the English scientist Robert Hooke when looking at a piece of tissue in a two-lens microscope. Hooke was able to visualize small cavities in the experiment piece, then naming such cell cavities.
Only a century and a half after the discovery of the cell, that the Cell Theory was launched, replacing the theory of spontaneous generation (or abiogenesis).
Before that, many scientists were already busy understanding the structure and functioning of the cell, generating knowledge that became fundamental to the development of biology, specifically cytology, a branch of science that studies the structure, functions and development of cells.
The answer is C and D.
I hope this helps. Good luck!
A evolution of populations
Explanation:
Most diving birds have (relatively) long necks and shorts legs, although their necks aren't as long as say herons, storks or egrets. Take the common loon for instance. Their necks can be up to half as long as their bodies but their legs are so short and set so far back that they are very awkward on land.