根据句子要求, 用括号中词的正确形式填空，并将答案写在答题纸相应题号的横线上。
Mum asked children to eat it           (two) a week.
It’s very important for students           (sleep) eight hours a night.
How many         (foot) does a dog have?
Don't ________ (worried) about your English. I can help you.
Your advice sounds ___________ (interest).
This song is very popular in many             (west)countries.
Thanks for your           (invite) to your house next week.
His bag is not as          (heavy) as mine.
Which one is a little           (far), this one or that one?
She likes to have friends who are           (difference) from her.