剑桥雅思4，test 1，reading 1里有句句子实在疑惑。

就是那篇孩子对热带雨林的错误理解的那篇
It seems schools may not be providing an opportunity for children to re-express their ideas and so have them tested and refined by teachers and their peers.
1. may not be providing, provide为什么要+ing?属于什么时态？be后面不是应该是被动态吗？
2. have them tested，应该是现在完成时吧，为什么have放在them的前面？
望指教，谢谢。

1, be providing是现在进行时态，因为前面有情态动词may，所以be动词是原形。如果没有may这个表示推测的情态动词的话，这个句子就是schools are providing an opportunity……
2, have sth/sb done是一个固定搭配，有被动的成分在里面。例如，我想打扫房间。可以翻译为：I want to clean my room 或者 I want to have my room cleaned（我想要我的房间被打扫）。

2 have sb do sth 表示让某人做某事，而非完成时态