【单选题】
<imgsrc="http://121.251.253.213/doc/a@9869E09EAF43605DEA686A47F51A268B.png/download?time=636002424844710630&token=3D81364A57C5910712E8421E058F4DFB&filename=png"data-preview_url_ueditor="doc/a@9869E09EAF43605DEA686A47F51A268B.png"data-url="doc/a@9869E09EAF43605DEA686A47F51A268B.png"/>
④
<imgsrc="http://121.251.253.213/doc/a@CF1BE005D8413A8F3A904618D0778415.png/download?time=636002424987918882&token=9C9A326147FAB1EC1580EE862DDAA93A&filename=png"data-preview_url_ueditor="doc/a@CF1BE005D8413A8F3A904618D0778415.png"data-url="doc/a@CF1BE005D8413A8F3A904618D0778415.png"/>
【单选题】
<imgsrc="http://121.251.253.213/doc/a@457B33C69788927B97EE709CCEE252B8.png/download?time=636002410647749695&token=781D4497E11B3670D9CCD8D1B59E3809&filename=png"data-preview_url_ueditor="doc/a@457B33C69788927B97EE709CCEE252B8.png"data-url="doc/a@457B33C69788927B97EE709CCEE252B8.png"/>
①
<imgsrc="http://121.251.253.213/doc/a@A54FF12616A47922F2C33DB081579836.png/download?time=636002410722629826&token=0511666BAE50F73C0EA8D99628F854FF&filename=png"data-preview_url_ueditor="doc/a@A54FF12616A47922F2C33DB081579836.png"data-url="doc/a@A54FF12616A47922F2C33DB081579836.png"/>
②
<imgsrc="http://121.251.253.213/doc/a@6ED0C0B76FD3C5879D169894755AE8BE.png/download?time=636002410840098032&token=8CC944AF7540098611C88DE9976000EB&filename=png"data-preview_url_ueditor="doc/a@6ED0C0B76FD3C5879D169894755AE8BE.png"data-url="doc/a@6ED0C0B76FD3C5879D169894755AE8BE.png"/>
③
<imgsrc="http://121.251.253.213/doc/a@899EDA616127ED81EA199B36DA1042CD.png/download?time=636002410929486189&token=E34E047DA33366C6B2270424EF901842&filename=png"data-preview_url_ueditor="doc/a@899EDA616127ED81EA199B36DA1042CD.png"data-url="doc/a@899EDA616127ED81EA199B36DA1042CD.png"/>
④
<imgsrc="http://121.251.253.213/doc/a@CBE8C80103D1EBD715F7A25059F97918.png/download?time=636002411045082392&token=9322A96C93EAFF8C8E0ABBC50DF4B253&filename=png"data-preview_url_ueditor="doc/a@CBE8C80103D1EBD715F7A25059F97918.png"data-url="doc/a@CBE8C80103D1EBD715F7A25059F97918.png"/>
【单选题】
<imgwidth="438"height="35"alt=""src="http://file.open.com.cn/ItemDB/3348/c90f4ed4-6261-46d8-9033-5b142c292889/20093181082534.JPG"/>
【单选题】
X与Y独立且DX=16,DY=9,则D(X+Y)=()。
【单选题】
<imgsrc="http://121.251.253.213/doc/a@0178FDE7FA9749BA391C5F58C6EB868A.png/download?time=636002427669563592&token=DD334D197FB1784D1AE96753F9BACA01&filename=png"data-preview_url_ueditor="doc/a@0178FDE7FA9749BA391C5F58C6EB868A.png"data-url="doc/a@0178FDE7FA9749BA391C5F58C6EB868A.png"/>
【单选题】
已知某种型号的雷管在一定刺激下发火率为1/5,今独立重复地作刺激试验,直到发火为止,则消耗的雷管数为3的概率为()。
【单选题】
设X与Y独立同分布,记U=X-Y,V=X+Y,则U、V必然()。
【单选题】
<imgwidth="472"height="59"alt=""src="http://file.open.com.cn/ItemDB/3348/1a20a59d-cb05-4017-82cb-4830fb48db5f/200931893552543.JPG"/>
【单选题】
<imgsrc="http://121.251.253.213/doc/a@4694669459F98E149B804A104B651936.png/download?time=636002388033637975&token=7717EBCF989826B9F937ADD750BA053E&filename=png"data-preview_url_ueditor="doc/a@4694669459F98E149B804A104B651936.png"data-url="doc/a@4694669459F98E149B804A104B651936.png"/>
①
<imgsrc="http://121.251.253.213/doc/a@7EFEDE86BAD9C681AE62991E99C4662F.png/download?time=636002388171386217&token=009F46715F7C1A9E4906033D77BCD786&filename=png"data-preview_url_ueditor="doc/a@7EFEDE86BAD9C681AE62991E99C4662F.png"data-url="doc/a@7EFEDE86BAD9C681AE62991E99C4662F.png"/>
②
<imgsrc="http://121.251.253.213/doc/a@BE3A648FAC9629C1B629016716F329E7.png/download?time=636002388290102425&token=84F498C616261DBEF529416490694BE4&filename=png"data-preview_url_ueditor="doc/a@BE3A648FAC9629C1B629016716F329E7.png"data-url="doc/a@BE3A648FAC9629C1B629016716F329E7.png"/>
③
<imgsrc="http://121.251.253.213/doc/a@C946EAF87FEE814E0E75113AFBE7F8BF.png/download?time=636002388403670625&token=96745AF8F4C3C6996032298D6EB273B9&filename=png"data-preview_url_ueditor="doc/a@C946EAF87FEE814E0E75113AFBE7F8BF.png"data-url="doc/a@C946EAF87FEE814E0E75113AFBE7F8BF.png"/>
④
<imgsrc="http://121.251.253.213/doc/a@34C0A8A82E9F963C042EC0805245E5F3.png/download?time=636002388507254807&token=F9769CD3B7EFA723D4FDACBD5CECC721&filename=png"data-preview_url_ueditor="doc/a@34C0A8A82E9F963C042EC0805245E5F3.png"data-url="doc/a@34C0A8A82E9F963C042EC0805245E5F3.png"/>
【单选题】
<imgwidth="573"height="70"alt=""src="http://file.open.com.cn/ItemDB/3348/9474d1c7-6260-47b7-88a6-f323c0d82a05/200931893822728.JPG"/>