Does it make any difference __________ he refuses or accepts the invitation?

Is it the years  _______  you worked in Africa as a doctor  _______  have a great effect on your literary works? 

.Heavy drinking used to be acceptable, but as drunken driving has caused so many tragedies public opinion is no longer________.

The medicine is on sale everywhere. You can get it at ___ chemist’s.

We must keep our room clean, for dirt and disease go______, you know.