We must keep_______exercise to keep heathly为什么填doing

We must We must value what we We must ( )(work)hard. we must call the We must help them? we must help it why we must sleep We must learn it we must find a We must purify the “we must study them.是“we must study them. we must keep our classroom( ). we must ( ) our school nuiforms ( we must start tomorrow morning. We must ___(be) careful. So We must Study hard we must do more英译汉 We must be strict_____ourselves_____our work.