Both his parents look sad. Maybe they ________ what happened to him.
Cats and tigers are animals of the cat family(猫科动物),so cats ______ tigers in many ways.
My ______ sister who works in the bank is two years ______ than I.
—Thanks a lot! ______ your help, I can’t do it so well.—With pleasure.
The shoes were worn out, what’s more, they aren’t worth _____.
—Which do you prefer, milk or coffee?—I like ______ of them. Tea is my favorite.