As far as possible, the teacher should expose the student to real life situations.
教师应该尽可能使学生接触现实生活的情景。
A colt you may break,but an old horse you never can.
小驹犹可练,老马最难驯。
After switching on powerful arc lights, they saw great stalagmites -- some of them over forty feet high -- rising up like tree-trunks to meet the stalactites suspended from the roof.