Please help in this question

There are six elements that make up most of the human body. which of the following is not one of these six elements?

In what layer of the sun is energy transfers between atoms

Ascience research group is testing a new type of plant food. one trial is conducted in a controlled experiment. the data from the trial show that the plant that received the new food grew faster than the control plant. the group announces that the new plant food makes plants grow faster. what is the main weakness in this scientific claim?