题目

From 2008 on, Liu Xiang _________ a lot from his foot problem, but he did not give up.A.supposed B.suffered C.surfed D.shut 答案：【答案】B【解析】句意：从2008年开始，刘翔饱受脚伤之苦，但他没有放弃。考查动词辨析。supposed认为；suffered遭受；surfed在……冲浪；shut关闭；根据“…from his foot problem”可知，这里表示“遭受……痛苦”，短语是suffer from…，故选B。 糖类不含有，脂类不一定有，蛋白质也不一定有，而核酸一定有的元素是 [　　] A．N B．P C．S D．Fe