A．It is second-hand information and useless.
B．It is gathered from other sources rather than from its inhabitants.
C．It is from the arguments about the country.
D．It is different from what one had before the travel.

A．Teach students the right way of thinking.
B．Point out students’ mistakes and correct then.
C．Give students correct answers and let them work on their own.
D．Ask students work out the right answer first and explain to them later.