More than 700 students, 100 volunteers and many landfill workers.
题干:谁参加了托马斯·丹博的“未来森林”活动?
根据第三段第1-2行:More than 700 students,100 volunteers and many landfill workers joined in. 超过700名学生、100名志愿者和许多垃圾填埋工人参加了活动。
可知,答案为More than 700 students, 100 volunteers and many landfill workers.