已知切割后的圆柱主、俯视图，左视图正确的是()。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201810/81b1ea8586be4e9ea3d3d7bebb35822b.png

被截切后的圆柱，左视图正确的是（ ）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201906/a3ab38cab70749ceafbd281e5f426384.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201906/07d930dcefc444369b0883e3275f04ff.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201906/069a9defdd8642fbbe98031516cf5e79.png" /> D: 都不正确

如主视图所示，三棱锥被截切，俯视图和左视图正确的是（ ）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201906/f6dde245be3a4ac286b637f07e1484fc.png"> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201906/04ae2221fc904cc1ac1caca4daaa8ab1.png"> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201906/e451d56ab1524240b603f2fa47aad33b.png"> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201906/0550413aeb5b436c88589bf8de2029af.png">

完成圆锥被切割后的俯视图，并补画左视图。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201806/c490f3f4924647c790f66b47d4bf4ad6.png

根据主、俯视图，分析相邻表面的连接关系，选择正确的左视图（ ）。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201811/bf54862850a249d39b3036abcc7497c2.png