---___________ do they visit their old friends?---Once a year.A How long B How oftenC How many times D How much time
While I _____ my homework in my room, my mother _____ in the kitchen.
We ____ _each other since I left Shanghai.
—Did that sportsman win ____ gold medal at ____Athens Olympics? —Yes, he did.
— Thank you for sharing your ruler with me. —That’s what friends are for.
You never know how much difficulty we had the problem. Luckily, we managed to solve it with Ms Zhu’s help.