Having a trip abroad is certainly good for the old couple, but it remains _______ whether they will enjoy it.
Old memories are often ____ when you hear a particular song or a piece of music.
Do you mind if I ____with my work while you are getting tea ready?
The gentleman does not ____the argument but watches the other guests.
If people keep polluting the rivers, no fish there will survive ___.
____ the weather, the athletic meetings will be held on time.