—Is this Mr White's office, Mary?—Yes, ________.
280. Take on a(n)__________ with you. It looks like raining.
279. The Palace Museum has many art treasures. In this sentence, "treasure" means ____.
278. The road constant improvements can’t keep pace with the increasing ____ .
277. If you want to get there quickly, you'd better take the track in the forest. The underlined word means ____.
276. We should take good care of our ____. Don’t forget to rinse your mouth after meals.