. Explain how fair testing can be done in this investigation

Conducting a fair test is one of the most important ingredients of doing good, scientifically valuable experiments. To insure that your experiment is a fair test, you must change only one factor at a time while keeping all other conditions the same. Scientists call the changing factors in an experiment variables.

i believe it is

1. 저는 사과를 머거요.

2. 너는 자야지.

3. 재석는 앉어 있었다.