Do you know the activity called “________ Lights” ?—Oh,it’s an activity that reminds people of saving energy.

The possibility _________ we won’t produce enough goods troubles everyone here.

People _______ the southwest of China were in great need of water a couple of months ago. [ ]

While teaching students, teachers should take into consideration ______ students develop at different rates.

The story was written in _____ easy English ____ even the seven-year-old boy could understand it.