--Why did the teacher the boy? --Because he helped an old man.
The sign(标志牌)made us safe.
Everyone should play a part in _____the earth.
-- ________ will Mr. Green be back? -- In a week, I think.
It's easy ______ a banana milk shake. Let me help you.
A: How do you make fruit salad? B: ______ cut up three bananas and a watermelon.Next put them in a bowl.