答：網球場是(shi)一(yi)塊(kuai)由邊(bian)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)、端(duan)(duan)(duan)(duan)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)、中(zhong)(zhong)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)、發(fa)(fa)(fa)球(qiu)(qiu)(qiu)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)和(he)中(zhong)(zhong)點(dian)組成的(de)(de)(de)長(chang)方形的(de)(de)(de)場(chang)地(di)。球(qiu)(qiu)(qiu)場(chang)兩(liang)邊(bian)的(de)(de)(de)界(jie)(jie)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)叫(jiao)(jiao)(jiao)(jiao)(jiao)邊(bian)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)，邊(bian)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)長(chang)23.77米(78英(ying)(ying)尺(chi)(chi)(chi)(chi))。在(zai)距球(qiu)(qiu)(qiu)網兩(liang)側6.40米(21英(ying)(ying)尺(chi)(chi)(chi)(chi))長(chang)的(de)(de)(de)四條(tiao)單(dan)打(da)邊(bian)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)除起著(zhu)判(pan)定(ding)單(dan)打(da)擊。球(qiu)(qiu)(qiu)是(shi)否(fou)(fou)出(chu)界(jie)(jie)(邊(bian)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)出(chu)界(jie)(jie))的(de)(de)(de)作(zuo)(zuo)用(yong)外，還(huan)起著(zhu)判(pan)定(ding)發(fa)(fa)(fa)球(qiu)(qiu)(qiu)是(shi)否(fou)(fou)界(jie)(jie)外(發(fa)(fa)(fa)球(qiu)(qiu)(qiu)邊(bian)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)出(chu)界(jie)(jie))的(de)(de)(de)作(zuo)(zuo)用(yong)。球(qiu)(qiu)(qiu)場(chang)兩(liang)端(duan)(duan)(duan)(duan)的(de)(de)(de)界(jie)(jie)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)叫(jiao)(jiao)(jiao)(jiao)(jiao)端(duan)(duan)(duan)(duan)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)。單(dan)打(da)端(duan)(duan)(duan)(duan)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)長(chang)8.23米(27英(ying)(ying)尺(chi)(chi)(chi)(chi))(圖1)。雙打(da)端(duan)(duan)(duan)(duan)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)長(chang)10.97米(36英(ying)(ying)尺(chi)(chi)(chi)(chi))(圖2)，比(bi)單(dan)打(da)場(chang)地(di)海邊(bian)多1.37米(4 1/2英(ying)(ying)尺(chi)(chi)(chi)(chi))。端(duan)(duan)(duan)(duan)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)除起著(zhu)判(pan)定(ding)擊球(qiu)(qiu)(qiu)是(shi)否(fou)(fou)界(jie)(jie)外(端(duan)(duan)(duan)(duan)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)出(chu)界(jie)(jie))的(de)(de)(de)作(zuo)(zuo)用(yong)外，還(huan)起著(zhu)判(pan)定(ding)發(fa)(fa)(fa)球(qiu)(qiu)(qiu)員發(fa)(fa)(fa)球(qiu)(qiu)(qiu)時(shi)(shi)是(shi)否(fou)(fou)踏線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)違例(腳誤(wu))的(de)(de)(de)作(zuo)(zuo)用(yong)。在(zai)球(qiu)(qiu)(qiu)網兩(liang)側6.40米(2l英(ying)(ying)尺(chi)(chi)(chi)(chi))處的(de)(de)(de)場(chang)內(nei)(nei)(單(dan)打(da)球(qiu)(qiu)(qiu)場(chang)場(chang)內(nei)(nei))各(ge)畫(hua)一(yi)條(tiao)與球(qiu)(qiu)(qiu)網平(ping)行(xing)的(de)(de)(de)橫線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)叫(jiao)(jiao)(jiao)(jiao)(jiao)做發(fa)(fa)(fa)球(qiu)(qiu)(qiu)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)。聯結兩(liang)發(fa)(fa)(fa)球(qiu)(qiu)(qiu)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)的(de)(de)(de)中(zhong)(zhong)點(dian)，畫(hua)一(yi)條(tiao)與邊(bian)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)平(ping)行(xing)的(de)(de)(de)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)叫(jiao)(jiao)(jiao)(jiao)(jiao)做中(zhong)(zhong)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)，中(zhong)(zhong)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)與球(qiu)(qiu)(qiu)網成“十(shi)”字形，將(jiang)發(fa)(fa)(fa)球(qiu)(qiu)(qiu)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)與邊(bian)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)間的(de)(de)(de)地(di)面分(fen)成四個(ge)相(xiang)等的(de)(de)(de)區(qu)(qu)域，這個(ge)區(qu)(qu)域叫(jiao)(jiao)(jiao)(jiao)(jiao)做發(fa)(fa)(fa)球(qiu)(qiu)(qiu)區(qu)(qu)。發(fa)(fa)(fa)球(qiu)(qiu)(qiu)員只有將(jiang)球(qiu)(qiu)(qiu)發(fa)(fa)(fa)在(zai)規定(ding)的(de)(de)(de)發(fa)(fa)(fa)球(qiu)(qiu)(qiu)區(qu)(qu)內(nei)(nei)才算合(he)法發(fa)(fa)(fa)球(qiu)(qiu)(qiu)。在(zai)端(duan)(duan)(duan)(duan)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)的(de)(de)(de)中(zhong)(zhong)心，向(xiang)場(chang)內(nei)(nei)畫(hua)一(yi)條(tiao)10厘米(4英(ying)(ying)寸(cun))長(chang)、5厘米(2英(ying)(ying)寸(cun))寬的(de)(de)(de)垂直于端(duan)(duan)(duan)(duan)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)的(de)(de)(de)短線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)叫(jiao)(jiao)(jiao)(jiao)(jiao)做中(zhong)(zhong)點(dian)。中(zhong)(zhong)點(dian)將(jiang)端(duan)(duan)(duan)(duan)線(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)(xian)分(fen)成相(xiang)等的(de)(de)(de)兩(liang)部分(fen)。中(zhong)(zhong)點(dian)限制著(zhu)發(fa)(fa)(fa)球(qiu)(qiu)(qiu)員發(fa)(fa)(fa)球(qiu)(qiu)(qiu)時(shi)(shi)的(de)(de)(de)站位。