28.The university with two____campuses hasa student population of 50,000 in total.
It is required that students______ mobile phones at school, so seldom_______ them using one.
------Tom is never late for work. Why is he absent today? ------ Something _______ to him.
Roads in this mountain area used to be_______; people found it hard to travel here.
--- someone says something negative about me? ------Just ignore it.
Every time ______ I go to school, I am usually riding my bike, _____ I take a bus.