Our government should ____ stricter measures to make sure all food products meet the quality standards.
The professor referred to _____ yesterday.
He got completely _____ when he saw both Lucy and Lily, who are twin sisters.
--- Shall I open the window to let some fresh air in? --- No, _____
It ______ at the crossroads ______ he was killed in the accident the other day.
A good idea just ______ me — Let’s go swimming.