15.（ ）

(单选题)—Could you tell me ______ the difficult problem, please?—Not (单选题)When people work with one mind they can even ______ Mount Ta (单选题)Great attention should be put to ______our environment from (单选题)______ it is to skate on real ice! (单选题)Try your best. They will choose a person ______ they think i (单选题)—Why didn’t you answer the phone just now?—I’m terribly sorr (单选题)I’m glad that my parents have ______ of me buying a new car. (单选题)Your bed needs ______, I am afraid. (单选题)This morning he got up earlier ______usual. (单选题)The passage mainly tells us ______.