The excerpt is from an article that roberto read for science class called “using the scientific method to study tomatoes.”

the student performed an experiment to test his hypothesis about sunlight and plant height using two plants. he kept everything the same between two tomato plants except he exposed them to different amounts of sunlight. he also used a third plant as a control group, or a group in which no variables are manipulated to confirm the results.
roberto critiqued the work. which problem did roberto most likely identify?
the sample size is too small.
too many variables are manipulated.
it is not possible to keep the conditions the same.
controls should only be used in studies of animals.

i believe it would cause an increase of percipitation, though i could be wrong. so i would say b is the answer.

idk why hjggjhjkhj

a covalent bond, specfically triple bond

1. amino acid refers to the fundamental building block of proteins, comprising of an amino group and a carboxyl group.

2. catalyst refers to any substance, which increases the rate of chemical reaction without being used up in the reaction.

3. a complex molecule containing he genetic code is dna or deoxyribonucleic acid.

4. an enzyme refers to a molecule of protein, which is unique in accelerating up a particular chemical reaction in the biological systems.

5. nucleic acid refers to an sequence of sugars, phosphates, and nitrogenous bases, for example, dna and rna.

6. a protein refers to a large, composite organic molecule comprising of a huge number of amino acids associated together with the of peptide bonds.

7. rna refers to a nucleic acid that takes part in the production of proteins.

8. substrate refers to a compound, which takes part in a chemical reaction, and is chemically modified by the reaction.