设<imgwidth="18"height="18"v:shapes="_x0000_i1034"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image008.png">为<imgwidth="14"height="16"v:shapes="_x0000_i1035"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image004.png">阶方阵,<imgwidth="18"height="18"v:shapes="_x0000_i1036"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image010.png">是<imgwidth="18"height="18"v:shapes="_x0000_i1037"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image008.png">经过若干次矩阵的初等变换后得到的矩阵,则有()
①
<imgwidth="64"height="22"v:shapes="_x0000_i1038"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image012.png">
②
<imgwidth="66"height="22"v:shapes="_x0000_i1039"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image014.png">
③
若<imgwidth="54"height="22"v:shapes="_x0000_i1040"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image016.png">,则一定有<imgwidth="54"height="22"v:shapes="_x0000_i1041"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image018.png">
④
<imgwidth="54"height="22"v:shapes="_x0000_i1042"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image020.png">,则一定有<imgwidth="54"height="22"v:shapes="_x0000_i1043"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image022.png">