1[单选题]

<p style="TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 0cm 0cm 0pt; FONT-FAMILY: 'Times New Roman'; TEXT-ALIGN: justify"><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体">方程<span><img style="VERTICAL-ALIGN: middle" height="44" width="123" src="http://www.jxjypt.cn/Content/Scripts/ewebeditor10/uploadfile/exam/201307/20130710152550869001.gif"></span>所表示的图形是<span>(<span>&nbsp;&nbsp;&nbsp; </span>)</span></span></p>
<p style="TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 0cm 0cm 0pt; FONT-FAMILY: 'Times New Roman'; TEXT-ALIGN: justify"><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体"><img style="VERTICAL-ALIGN: middle" height="21" width="27" src="http://www.jxjypt.cn/Content/Scripts/ewebeditor10/uploadfile/exam/201307/20130710152550289002.gif"></span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体">单叶双曲面<span><span>&nbsp;&nbsp; </span><span>&nbsp;&nbsp;</span><span>&nbsp;</span><span>&nbsp; </span><img style="VERTICAL-ALIGN: middle" height="21" width="27" src="http://www.jxjypt.cn/Content/Scripts/ewebeditor10/uploadfile/exam/201307/20130710152550234003.gif"></span>双叶双曲面<span><span>&nbsp;&nbsp; </span><span>&nbsp;&nbsp;&nbsp;&nbsp;</span><span>&nbsp;</span><img style="VERTICAL-ALIGN: middle" height="21" width="27" src="http://www.jxjypt.cn/Content/Scripts/ewebeditor10/uploadfile/exam/201307/20130710152550751004.gif"></span>椭球面<span><span>&nbsp; </span><span>&nbsp;</span><span>&nbsp;</span><span>&nbsp;&nbsp;</span><img style="VERTICAL-ALIGN: middle" height="21" width="28" src="http://www.jxjypt.cn/Content/Scripts/ewebeditor10/uploadfile/exam/201307/20130710152551964005.gif"></span>双曲抛物面</span></p>

A.A

B.B

C.C

D.D