It is important to have your eyes examined regularly to check for any sign of eye disease that may not have any ________.
——-Shall we go out for a walk? ——Sorry. This is not the right ____ to invite me. I am too tired to walk.
It is clear that the whole world is passing through a social revolution in which a central _____ must be taken by scientists and technologists.
The author of the report is well _____ with the problems in the hospital because he has been working there for many years.
With the change of the economic foundation the entire immense superstructure is _____ rapidly transformed.
Even if they are on sale, these refrigerators are equal in price to, if not more expensive than, _____ at the other store.