Question

In those days, we had no phones, so we had to keep in touch ________ letters often.

A．with

B．of

C．on

D．through

Answer 1

D

试题分析：句意：在那些过去的日子，我们没有电话，因此我们不得不经常通过书信保持联系。keep in touch through表示通读…保持联系。根据句意，故选D。