题目

The volunteers __________ many signs to remind people to protect the environment.A. put through B. put up C. put in D. put out 答案：【答案】B【解析】句意：志愿者们张贴了许多标语来提醒人们保护环境。A. put through完成、使经历、接通； B. put up张贴、挂起；C. put in放进去；D. put out扑灭。“张贴”标语，符合语境。故选：B。