A．sailingB．failingC．tryingD．hopingWhile attempting to f……

单项选择题The immense change of the city astonished every member of the conference.

单项选择题Jim has gained so much weight that a lot of his clothes don't fit him any more.

单项选择题We want to know his family background.

单项选择题All living organisms, regardless of their unique identity, have certain biological, chemical, and physical characteristics in common.

单项选择题Practically all species of animals communicate either through sounds or through a large repertory of soundless codes.