What only happens during a chemical reaction?
a. a solution is made.
b. new substances are formed.
c. bubbles form.
d. colors change.

What is the farthest destination to date for a human spaceflight mission?

Pls me i need this ! each cell has genes activated depending on it's job and what kind of cell it is. it is the presence of that causes the repressor protein to fall off and unblock the gene on the lac operon. if a gene is turned on then it is being an additional circular chromosome found in some bacteria that is used in genetic engineering.

Why are carbon dioxide concentrations expected to increase? a carbon dioxide concentrations are expected to increase, because fossil fuel burning is expected to increase b. carbon dioxide concentrations are expected to increase, because of an increase in agriculture. c. carbon dioxide concentrations are expected to increase, because more land will have to be cleared for increasing populations and agricultural use. d. all of the above select the best answer from the choices provided mark this and return save and exit next submit submit