Study sentences a-f in the texts and tick the best choice. 1) These sentences sound better in the passive than in the active because we are more interested in the … (1) a. actions b. people c. time 2) Which auxiliary verb do we use in every sentence (2) a. have b. be c. do 3) Every passive sentence has a(n) … (3) a. infinitive(不定式) b. -ing form c. past participle（过去分词） 4) To mention the person or thing that does the action we use the word … (4) a. because b. by c. for__4__(完形填空) .a .b .c
