Is Richard still living here —No, he to Paris already.

he field research will take Joan and Paul about five months; it will be a long time _______ we meet them again.

The growing speed of a plant is influenced by a number of factors, ____ are beyond our control.

Jack is someone ______ you will miss a lot after you leave school.

Would you like to play computer games with me—Sorry, I have ______ playing them.