I had great difficulty ______ the suitable food on the menu in that restaurant.
______ twice a year,whether it is a car or a truck,is the rule that every driver must obey in this city.
—Please ______ us in the discussion.—I'd like to,but I'm ______busy at the moment.
—Johnson,come and look at the sea!It's beautiful,isn't it?—Absolutely!If only I ______here by the sea.
It is you as well as your wife that ______ your son's bad performance at school.
These problems,______ will seriously affect the growth of teenagers and even the nation's future.