Can somebody please help me

Which of the following group roles has the responsibility of keeping the discussion on schedule?

Which sentence best contrasts two things? a. air travel, like bus travel, is a fun way to get from one place to another. b. air travel is a fun and relatively easy way to get from place to place. c. both bus travel and air travel require substantial planning. d. air travel is much more expensive than bus travel.

Hur ! asap what is the structure of the following sentence? although i have already visited africa, i would certainly like to return. a) compound b) compound-complex c) complex d) simple