If it ______ for his invitation the other day, I should not be here now.

(单选题)______ to the polluted air is dangerous for our health. (单选题)At present, there are many instances ______ the governments (单选题)The auto-company succeeded in developing a new type of new e (单选题)—What do you think of her suggestion?—______, it would be mu (单选题)My brother left home five years ago. I ______ nothing from h (单选题)He regretted ______ a second-hand car. (单选题)Please put these teaching materials in order and don’t leave (单选题)—What does the sign over there say?—No person ______ enter t (单选题)It’s the protection for the trees ______ really matters, ___ (单选题)I like this 3G cellphone very much, but it costs almost ____