They need twenty more workers ______ their group to do the job.

So hard-working _____ that he sets agood example to all the other classmates.

Little children should go to school to learn something.______, they should learn how to behave well in social life.[ ]

It is an abundance of cheap goods and quick delivery service ______ account for the fact that the number of Internet shopping on this website is four times ______ it was last year.

It is so cold in Antarctic that the penguins have to stand _______to each other to keep warm.