题目

（题文）I didn't accept his help ________ I wanted to try it myself.A. because B. thoughC. until D. unless 答案：【答案】A【解析】句意：我没有接受他的帮助，因为我想自己尝试。A. because因为； B. though尽管；C. until直到；D. unless除非。根据题意，故选A。鱼、肉、蛋中富含营养素是________．