一个初中英语问题-----------高手帮忙
A：Doctor,I’m not feeling well.
B：What’s the matter,madam?
A：I often feel tired when I do the cooking.
B：Oh,I’m afraid you are too fat and didn’t【take enough exercise】.
A：But how can I get fit,doctor?
B：If you want to get fit,you have to eat less food and【take more exercises】.
请解释第一个【】里的exercise与第二个【】里的exercises.
为什么一个用单数,一个用复数,还是出题人输入笔误?