2019-2020123361ABCD2+y=13x2y=15xy=1+y=1A1B2C3D430.001239g/cm3A1.239103g/cm3B1.239102g/cm3C0.1239102g/cm3D12.39104g/cm34OABCO12ABCD5Ax6x2=x3Bx1=C2x32=4x6D2a2?a3=2a66ECDABCDA1=2B3=4C5=BDB+BDC=180712122A1+2B1C12D128ABCD9AAOE=2AOCBAOCAOBCCOD+EOD=COEDDOE=BOC10x+ax+b=x2kx+abkAa+bBabCabDba1111=223=432+4=9044+5=180A1B2C3D412100002.5%0.5%2210000xyABCD64241383014xyxy15am+1bn+2?a2n1b2n=a5b3m+n16DEBCBEABCADE=601=17ab183x22x+1xbxb60191x2yx+2y1+4y22a2b[ab22+2ab3+3a2]201221ABCDOOEAODFOC=901=4023221=23=45=6EDFB232x+a3x+ba6x2+11x10x2x29x+10ab24200671920800T22T223545T222019-2020123361ABCDABCDAABBCCDDB2+y=13x2y=15xy=1+y=1A1B2C3D4+y=13x2y=15xy=1+y=12B30.001239g/cm3A1.239103g/cm3B1.239102g/cm3C0.1239102g/cm3D12.39104g/cm31a10n00.001239=1.239103A4OABCO12ABCD18090121+AOC+2=180ABCOAOC=901+2=90B5Ax6x2=x3Bx1=C2x32=4x6D2a2?a3=2a6Ax6x2=x4Bx1=C2x32=4x6D2a2?a3=2a5C6ECDABCDA1=2B3=4C5=BDB+BDC=180B3=4ABCDC5=BABCDDB+BDC=180ABCDA12ACBDAD1=2ACBDAA712122A1+2B1C12D1221121+2=1801+2=902=18012=90=190=11+2=12C8ABCD23yC9AAOE=2AOCBAOCAOBCCOD+EOD=COEDDOE=BOCCOE=90AOC=90COE=90AOE=180AAOC=90AOB90BCOE=DOC+DOECDOECOBDD10x+ax+b=x2kx+abkAa+bBabCabDbakx+ax+b=x2+a+bx+ab=x2kx+aba+b=kk=abB1111=223=432+4=9044+5=180A1B2C3D411=223=444+5=1809032+4=90D12100002.5%0.5%2210000xyABCD222.5%0.5%xyB64241383075128302.512308302.530=757514xyxy1xy2x2y=2xy=1115am+1bn+2?a2n1b2n=a5b3m+nmnm+nam+2nb3n+2=a5b3m=n=m+n=16DEBCBEABCADE=601=30DEBCADE=60ABCBEABC1DEBCADE=60ABC=ADE=80BEABC1=ABC=303017ab5ab+4a=8a=22b=6b=3ab=23=55183x22x+1xbxb2b+1=03x22x+1xb=3x33bx22x2+2bx+xb=3x33b+2x2+2b+1xbx2b+1=0b=60191x2yx+2y1+4y22a2b[ab22+2ab3+3a2]121=x2yx+2yx+2y+4y2=x24y2x+2y+4y2=x2x+2y2=a2ba2b4+8a3b3+3a2=a4b5+8a5b4+3a4b2012121x=y+42y+8+y=5y=1y=1x=3256x=3x=0.5x=0.5y=521ABCDOOEAODFOC=901=4023FOC=901=4033AODAODOEAOD2FOC=901=40AB3+FOC+1=1803=1809040=503AODAOD=1803=130OEAOD2=AOD=65221=23=45=6EDFBABDEHEDFB1EHA3=4BDCF5=BAF5=6ABCD2=EHA1=EHABFDEBFDE3=4BDCF5=BAF5=6BAF=6ABCD2=EHA1=21=EHABFDEBFDE3=4BDCF5=BAF5=6BAF=6BFADEC180BFA=1+BFA+BAFDEC=2+4+61=2BAF=6BFA=4BFDE232x+a3x+ba6x2+11x10x2x29x+10ababab2xa3x+b=6x2+2b3axab=6x2+11x102b3a=11ab=102x+ax+b=2x2+2b+ax+ab=2x29x+102b+a=9ab=102x53x2=6x219x+1024200671920800T22T223545T223545800T22xmym/sT22100m20m/s