28．—You must be tired after the flight. You’d better take a good rest.—Yes, I _________. Thank you.

It is not until recently ______ thescientists have found proof of there being water on Mars

Storms most commonly occur_______a warm air mass and a cold air mass touch each other.

下面各句中，加横线词语运用正确的一项是 （ ）

She didn’t come to the party last Sunday. __________, she must have made the party more exciting.