We offered these students a summer course ,aimed _____ improving their spoken English． A．to B．in C．at D．for

If you don’t know the answer, don ‘ t be afraid_______so.

________young people see and hear in the media helps them to figure out how the world works.[ ]

my surprise, I got the first in the math competition.

It is uncertain __ side effect the medicine will bring about, although about two thousand patients have taken it