单项选择题
He was hit on the head by a piece of iron and was knocked ______ .
单项选择题 ______ the difficulty of the task, I shall be lucky to complete it by May.
单项选择题 What did he say in the letter I really can't ______ it out.
单项选择题 As soon as the exam was over, the students all went their ______ ways.
