--When did you get the gift? -- _____ my _____ birthday.
Some people plan to ______ a volunteer project to help the disabled children.
Pollution is a serious problem. Scientists will _______ some good ways to save it.
My father often cooks some delicious food _________for us at home.
— What did you see? — I saw many boys________ games near the river.
— What’s the trouble with you? 一I________ a headache.