I’m ___ duty today. I must clean the classroom _____school.

gh Beijing didn’t establish its first Antarctic research base until 1985, Chinese efforts _________ its influence across the continent are now outpacing other nation’s plans.

The lady got ________ X-ray and she showed ________ X-ray to the doctor.

Mary _______as a secretary in this company for twenty years and now she stays at home taking care of her own garden.

___ he will come is certain.