21．mary comes downstairs to ______ a customer complaining about the poor service. a. hear b. overhear c. see d. watch 22．as you ______ new words in context, it is a very good method for you to guess their meanings. a. come about b. come across c. come out d. come up 23. the river would soon ______ if it continued drought. a．die out b。dry out c．die away d。dry up 24. she is ________ a friend _____ a mother. a. rather---than b. more---than c. as---as d. preferring---to 25. he brings a lot of profits to the company. he ______ well of his boss. a. deserves b. is worth c. re
