Heturneddowntherequestofhisfriend

He turned down the request of his friend because it was     the limit of his powerA.beyondB.overC.offD.above

参考答案：
A解析考查介词，句意：他拒绝了朋友的请求，因为这个请求超出了他的权力范围。Beyond 超出范围，所以选A。