it's ()for us ()rainforests well Abad ,to protect B good,to protect C important,to protecting

问题描述:

it's ()for us ()rainforests well Abad ,to protect B good,to protect C important,to protecting

B,保护热带雨林对我们有益处. it作形式主语,不定式to protect rainforests well 是真正的主语.