21. To many teenagers the cellphone is not only _____useful tool but also ____ way to have fun and be cool.
—How can I wake up so early? —Set the alarm at 5:00 a.m., ________ you will make it.
________ I can see, there is only one way to solve this problem.
—I'm sorry, I shouldn't have been so rude to you. —You ________ your temper, but that's OK.
—Mr. Gordon asked me to remind you of the meeting this afternoon. Don't you forget it?—OK, I ________.
We want to encourage students to ________ the running of the college.