—Who is the man ______ by a group of students there?

—A professor _____ research on physics.

A．followed; did

B．following; did

C．followed; doing

D．following; doing

在广西壮族自治区，旅游经营者从事旅游经营活动，应当承担的义务包括（）。

A.依法履行合同

B.不得作出对旅游者不公平、不合理的规定

C.对旅游者合法权益造成损害的，依法承担法律责任

D.遵守法律、法规和社会公德