Jenny hopes that Mr Smith will suggest a good way to have her written English ____ in a short period [ ]

_______ word “PM 25” repeatedly appearing in________ media reports, the public can’t help wondering what it really means

___________ –Yes, I’d like some tea.

I didn’t become a serious climber until the fifth grade, _____ I went up to rescue a kite that was stuck in the branches of a tree.

当你向别人打招呼时,你不可以说“_______”.