The teacher asked more ______to prevent the students’ eyes from being injured.
E-mail, as well as phone calls, _____________ an important part in daily communication.
If we don’t take steps, some rare animals, such as the Tibetan antelopes and pandas will ____________ some day just as dinosaur.
------- How can we __________ to a changeable environment? -------- By constant study and changing our ideas.
----- How did you find _________ long talk given by the headmaster on ___________ Teachers’ Day? -------- Boring. I’d rather he had made it short.
21 ------ He runs his own company at the age of 21. ------- ___________________