As it was almost time for the flight, all the passengers got ______ the plane.

The conservation area is very important for preserving many animals and plants, which would ______ run the risk of becoming extinct.

  "It’s ______ warm today, let’s go swimming."　　　　"No, I don’t ______ to do. It’s ______ cold today.

Although modem organic food has become very popular, many people can' t figure out the difference between organic foods and ______ grown foods．

The demand for _____ skilled workers is still increasing.