send me your address once you received it.句中once 后的receive用原

avoid是及物动词,后面可以直接接名词,代词,动名词或者是接that从句。没有avoid sb。to do/doing结构。在这个题中是接的省略引导词that的从句。刚刚看到楼上说可以接happening,是不对的,如果要接的话,it要改为物主代词its才对。