独立方程<imgwidth="150"height="58"v:shapes="_x0000_i1118"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image114.png">则基础解系为()
①
<imgwidth="68"height="154"v:shapes="_x0000_i1119"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image116.png">
②
<imgwidth="82"height="154"v:shapes="_x0000_i1120"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image118.png">
③
<imgwidth="82"height="154"v:shapes="_x0000_i1121"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image120.png">
④
<imgwidth="68"height="154"v:shapes="_x0000_i1122"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image122.png">