被动语态专项练习 1.Thousands of trees over the mountain___ by the Young Pioneers last spring. A. planted B. were planted C. was planted D. have planted 2.To develop the west of China, a lot of new roads___ built. A. must B. has C. have D. must be 3.English is taught___ a foreign language in almost schools in China. A. with B. by C. as D. for