19. This kind of desk can be ________ to the height you need, which makes it very popular.
_______ entering the classroom, remember to take your seat and turn off your cell phone.
I worked as hard as I could _______ for the final exam.
Not only I but also Jane and Mary _______ tired of doing the same thing all the time.
Getting _______ in the forest is very dangerous. A. losing B to lose C. lost D. being lost
When traveling abroad, we should ______ learn more about local customs so as to avoid unnecessary misunderstanding during communication.