Cứuuuuuuuuuuuuuuuuuuuuuuuu

3. C

return all books by the due back date 

=> all books taken back on time

by the due back date ~ on time

return ~ taken back

4. A

leave any parcels with number 24, Monday to Friday

=> All post should be taken to number 24 on weekdays 

Monday to Friday~weekdays 

leave any parcels~All post should be taken 

5. A

had a temparature=> too ill

missed it=> not attend