New data fromUnited States Forest Service ecologists show that for every dollar spent oncontrolled smallscale burning, forest thinning, and the trainning of firemanagementpersonnel saves seven dollars on havingto extinguish.
这句错在哪儿，麻烦老师解答
第一要明确：1. spend+钱+on+sth 2. spend+钱+on+doing sth.如：1. She spent 1,000 yuan on a new dress. 2. I have spent 100 yuan on updating my computer systems.所以，原句中的controlled要改为controlling ;另外去掉for；注意saves的主语是every dollar，这两者之间从spent到personnel为后置定语.整个句子是强调预防失火的重要程度，防患于未然.