Misunderstandings________from lack of social communication，unless________properly，may lead to serious problems

He hardly caught the train yesterday afternoon, he, because he was caught in the rain.

I do think Tom’s conduct that evening was, to say ________， strange.

Following the girl, we went into a hall, on ____ walls hung a few pictures of some famous scientists．

We have made good preparation for the test, so there ____ be any problem with it. [ ]