108. Dr. Manette had been mentally ____ byhis long years alone in prison and his hair had turned white.

Nowadays, sending e-mails to each other has become a way ______________ what they think to others.

The director couldn’t figure out _______ made his assistant spend so much time in doing the survey. [ ]

The old tower must be saved, the cost.

_______ in traffic jam，he had no choice but to wait patiently.