She looks very sad. I want to help her, but I just don’t know ____ to do it.

He comes _____ England now he lives _____ Nanjing.[ ]

Where do you often exercise?—I often exercise in the park. It’s close to my house.[ ]

Where is the cat?—It’s_____ the chair. [ ]

Areyougoingthere_____bikeor_____foot. [ ]