I have many friends, ________ some are businessmen.
_____more and more forests destroyed, some animals are facing the danger of dying out.
David’s effort was ______, because he won the first prize in the English speech contest, _____ made his classmates surprised.
.We have got a heavy snow there in my hometown this winter, which is a sign that this year _____ to be another good one for harvests.
—Who______ it be that is knocking at the door? —It ______ be Father, but I’m not sure.
The Smith’s family, which __________ a large one, ____________visit BeiJing this summer.