用方框中所词组的正确形式填空。每词只用一次。
laugh,   tooth,   little,  serious,   minute  
Lisa is _______ of us. She hardly ever smiles.
The bus ride usually takes us about 25_____ to get to school?
My baby brother has three _______ . He is too young to eat anything.
We must try to eat_______ meat. Too much meat is bad for our health.
He is very funny. He always makes his classmates _____.