请根据句意从方框中选择合适的单词，并用其适当形式填空，使句子通顺。

Elephants eat________, but they can move silently.
Food __________is very important for children.
She is ____________ among these girls, but she is still on diet.
A lot of people are having a party for the old lady’s __________ birthday.
—Is this your sister’s handbag? —No, it isn’t.. __________ is on the chair behind the desk.