"The lecture was boring and many students slipped out when the instructor turned towards the blackboard"
"three years elapsed"
slip away是什么意思
jerkily是什么意思
severely punish是什么意思
without a doubt是什么意思
debatably是什么意思
exploratory study是什么意思
exploratory operation是什么意思
examining是什么意思
torturer是什么意思
one or two是什么意思