Wei Ming and Wei Ling woke up late for school one day. In their rush, Wei Ming left his slice of bread in the oven, while Wei Ling shoved her slice of bread into the refrigerator.
Three days later, Wei Ming noticed that some parts of his bread had turned greyish
green, while Wei Ling's had not.
teor
(a) Suggest what happened to the bread left in the oven.
(b) The reason stated in Question 3(a) is your hypothesis for the experiment. Pose a
question to test your hypothesis.
(c) (i) State the variable that should be changed during the experiment.
(ii) State one variable that should be kept constant for the experiment.
(iii) Suggest how the result may be affected if the variable stated in Question 3(c)(ii)
is not kept constant.