Can anyone help me with this question. is there anybody who is an expert in science??

Which of the following represents the ester functional group? a. -coo- b. -cho c. -cooh d. c=o

Scientists often have to deal with numbers that are either very large or very small. for example, the radius of the sun is approximately 696,000 kilometers, while bacterial cells are as small as 1.9 × 10-4 millimeters. express each number in an alternate form.

Which of the following is a solution a- brewed coffee b-tomato juice c- ranch salad dressing d- muddy water