大全968

968. Interest rates on mortgages have declined steadily during the first six months of this year but virtually remained unchanged during the next three months

(A) have declined steadily during the first six months of this year but virtually remained unchanged

(B) declined steadily during the first six months of this year but virtually remain unchanged

(C) steadily declined during the first six months of this year but remain virtually unchanged

(D) declined steadily during the first six months of this but have remained virtually unchanging’

virtually unchanging’（E）

(E) declined steadily during the first six months of this year but have remained virtually unchanged

請問一下,為什麼前面用過去式,後面用現在完成式呢?我只知道現在式和現在完成式,過去式和過去完成式,現在式和過去式之間有先後關係.

Only E has the possibility to be correct- the next three months may last until the moment when the sentence was written.

during: this preposition is tricky, most of the times it doesn't stay with perfect tense, however, it can be used with perfect tense.

我懂了,謝謝

那么过去完成时态怎么用，如果A改成：had declined steadily during the first six months of this year but virtually remained unchanged，对吗？这里的virtually放在remained之前和之后有区别吗？谢谢！

还有，tianwan的帖子里用了have possibility to be...，这种用法对吗？不是说possibility后面只能用of being这种形式吗？tianwan NN，不要在意，只是不明白，讨论一下。

I made a mistake. Thanks.

1, during 很少用完成时，但during可以用完成时，估计这里用完成时是说明后3个月是至今。

2，对仗。