A．onB．ofC．atD．by

【C18】A．onB．beforeC．atD．in

【C10】A．onB．inC．atD．from

【C10】A．OnB．UponC．AtD．For

【C17】A．onB．ofC．atD．in

【C6】A．inB．ofC．atD．to

There are trees ____ all shapes on the hill.A: inB: ofC: atD: by