____ in these years have we changed the prices of these products.

问题描述:

____ in these years have we changed the prices of these products.
A.Not once B.Two chances
C.Three times D.Once
87.141

A.句首为否定形式时句子要用部分倒装.have we changed 使部分倒装形式,因此选A,只有这个是否定的句意:这些年我们不止一次改变了这些产品的价格.once在这里是一次的意思.