I don’t believe we _______ before —Well, I saw you once at a party, but we ______ introduced

d you like to go to the cinema withme this evening— I’d like to, but I won’t be free tonightLet’s make ____ some other day

.The Forbidden City is an area ＿＿ once only the emperor, his family and officials were allowed

下列加点字的注音都正确的一组是（ ）

What does PM 2.5 mean—It’s a professional ________ indicating the condition of air pollution.