5. I have a stomachache.
我肚子疼。
还能这样说：
I have a belly ache.
I have got pains in my belly.
谚语：
Do not do to others what you would not like done to you.
己所不欲，勿施于人。
6. My head hurts.
我头疼。
还能这样说：
My head is pounding.
I have a splitting headache.
7. I don't have any appetite.
我没有食欲。
还能这样说：
I'm suffering from lack of appetite.
I have no appetite at all.
谚语：
Appetite comes with eating.
食欲越吃越旺。
8. I've been feeling a little nauseous.
我一直想吐。
还能这样说：
I feel queasy and sick.
I've been felling like throwing up.
应用解析：
in little 小规模地;小型地;
make little of 不重视，不以……为意;
no little 许多;
not a little 许多;很;
the little 无足轻重的人;仅有的一点;