I often chat with my friends on the Internet.— You are so smart! Will you please tell me____

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

In dealing with public relations,we should make every effort to prevent the __________ in personality.

E-Commerce ______ mislead customers at times eventhough it’s more convenient and faster in general.

er, youpromised!—Well,____But it was you who didn’t keep your word first