He turned his head and look about him to manke absolutely su

1.翻译：他掉转头来,并且四下打量他,想要完全地确定.
2.此句的look about中的about是介词,意思是“在...周围/四处”.
不过,此短语中的about也可以做副词,意思是“在四处/到处”.
如：He looked about(介词) the classroom.= He looked about(副词) in the classroom.
他四处观看这个教室.= 他在教室里面四处看.
3.而him就是介词about的宾语,表明该动作的范围.