-Is the man over there your English teacher ? --No, it ______ be him. He has gone to Canada to study further.
Frank often wears a mask ________he can keep fit in the foggy and hazy (霾) weather.
Poor Tim is too nervous to start his speech. Someone should remind him________.
Make a list of the things you want to buy. ________, you will surely forget some of them.
— Excuse me. Would you mind my using your dictionary for a short time? —________.
― How was your weekend? ―________