My sister is only four years old, but she can look after ________ now.
—What do you think about the idea?—I am really against _________ a running race in the street.
—Do you know whose dictionary it is?—It ________ be Ann’s. Look! Her name is on the first page.
—Why does John look so sad? —Lingling _________her ice cream on his new shoe.
—The boy is ________for his age. —Yes, I was much _______when I was his age.
—What’s this? —It’s a machine which was invented in __________century in China.