答：網球場是(shi)一(yi)(yi)塊由邊(bian)(bian)線(xian)(xian)(xian)、端(duan)(duan)線(xian)(xian)(xian)、中(zhong)(zhong)線(xian)(xian)(xian)、發(fa)球(qiu)(qiu)(qiu)線(xian)(xian)(xian)和中(zhong)(zhong)點組成(cheng)的(de)(de)(de)(de)長(chang)(chang)方形的(de)(de)(de)(de)場(chang)地。球(qiu)(qiu)(qiu)場(chang)兩(liang)(liang)邊(bian)(bian)的(de)(de)(de)(de)界(jie)(jie)(jie)線(xian)(xian)(xian)叫(jiao)(jiao)邊(bian)(bian)線(xian)(xian)(xian)，邊(bian)(bian)線(xian)(xian)(xian)長(chang)(chang)23.77米(mi)(mi)(mi)(78英(ying)尺)。在(zai)距球(qiu)(qiu)(qiu)網兩(liang)(liang)側6.40米(mi)(mi)(mi)(21英(ying)尺)長(chang)(chang)的(de)(de)(de)(de)四條單打(da)邊(bian)(bian)線(xian)(xian)(xian)除起著(zhu)判(pan)定(ding)單打(da)擊(ji)。球(qiu)(qiu)(qiu)是(shi)否(fou)出界(jie)(jie)(jie)(邊(bian)(bian)線(xian)(xian)(xian)出界(jie)(jie)(jie))的(de)(de)(de)(de)作(zuo)(zuo)用外，還(huan)(huan)起著(zhu)判(pan)定(ding)發(fa)球(qiu)(qiu)(qiu)是(shi)否(fou)界(jie)(jie)(jie)外(發(fa)球(qiu)(qiu)(qiu)邊(bian)(bian)線(xian)(xian)(xian)出界(jie)(jie)(jie))的(de)(de)(de)(de)作(zuo)(zuo)用。球(qiu)(qiu)(qiu)場(chang)兩(liang)(liang)端(duan)(duan)的(de)(de)(de)(de)界(jie)(jie)(jie)線(xian)(xian)(xian)叫(jiao)(jiao)端(duan)(duan)線(xian)(xian)(xian)。單打(da)端(duan)(duan)線(xian)(xian)(xian)長(chang)(chang)8.23米(mi)(mi)(mi)(27英(ying)尺)(圖1)。雙(shuang)打(da)端(duan)(duan)線(xian)(xian)(xian)長(chang)(chang)10.97米(mi)(mi)(mi)(36英(ying)尺)(圖2)，比單打(da)場(chang)地海邊(bian)(bian)多1.37米(mi)(mi)(mi)(4 1/2英(ying)尺)。端(duan)(duan)線(xian)(xian)(xian)除起著(zhu)判(pan)定(ding)擊(ji)球(qiu)(qiu)(qiu)是(shi)否(fou)界(jie)(jie)(jie)外(端(duan)(duan)線(xian)(xian)(xian)出界(jie)(jie)(jie))的(de)(de)(de)(de)作(zuo)(zuo)用外，還(huan)(huan)起著(zhu)判(pan)定(ding)發(fa)球(qiu)(qiu)(qiu)員(yuan)發(fa)球(qiu)(qiu)(qiu)時是(shi)否(fou)踏線(xian)(xian)(xian)違例(腳誤(wu))的(de)(de)(de)(de)作(zuo)(zuo)用。在(zai)球(qiu)(qiu)(qiu)網兩(liang)(liang)側6.40米(mi)(mi)(mi)(2l英(ying)尺)處(chu)的(de)(de)(de)(de)場(chang)內(單打(da)球(qiu)(qiu)(qiu)場(chang)場(chang)內)各畫(hua)一(yi)(yi)條與(yu)球(qiu)(qiu)(qiu)網平行(xing)的(de)(de)(de)(de)橫線(xian)(xian)(xian)叫(jiao)(jiao)做發(fa)球(qiu)(qiu)(qiu)線(xian)(xian)(xian)。聯結兩(liang)(liang)發(fa)球(qiu)(qiu)(qiu)線(xian)(xian)(xian)的(de)(de)(de)(de)中(zhong)(zhong)點，畫(hua)一(yi)(yi)條與(yu)邊(bian)(bian)線(xian)(xian)(xian)平行(xing)的(de)(de)(de)(de)線(xian)(xian)(xian)叫(jiao)(jiao)做中(zhong)(zhong)線(xian)(xian)(xian)，中(zhong)(zhong)線(xian)(xian)(xian)與(yu)球(qiu)(qiu)(qiu)網成(cheng)“十(shi)”字形，將發(fa)球(qiu)(qiu)(qiu)線(xian)(xian)(xian)與(yu)邊(bian)(bian)線(xian)(xian)(xian)間的(de)(de)(de)(de)地面(mian)分(fen)成(cheng)四個(ge)(ge)相等的(de)(de)(de)(de)區(qu)域(yu)，這個(ge)(ge)區(qu)域(yu)叫(jiao)(jiao)做發(fa)球(qiu)(qiu)(qiu)區(qu)。發(fa)球(qiu)(qiu)(qiu)員(yuan)只有將球(qiu)(qiu)(qiu)發(fa)在(zai)規定(ding)的(de)(de)(de)(de)發(fa)球(qiu)(qiu)(qiu)區(qu)內才算合法發(fa)球(qiu)(qiu)(qiu)。在(zai)端(duan)(duan)線(xian)(xian)(xian)的(de)(de)(de)(de)中(zhong)(zhong)心，向場(chang)內畫(hua)一(yi)(yi)條10厘米(mi)(mi)(mi)(4英(ying)寸)長(chang)(chang)、5厘米(mi)(mi)(mi)(2英(ying)寸)寬的(de)(de)(de)(de)垂(chui)直(zhi)于端(duan)(duan)線(xian)(xian)(xian)的(de)(de)(de)(de)短線(xian)(xian)(xian)叫(jiao)(jiao)做中(zhong)(zhong)點。中(zhong)(zhong)點將端(duan)(duan)線(xian)(xian)(xian)分(fen)成(cheng)相等的(de)(de)(de)(de)兩(liang)(liang)部分(fen)。中(zhong)(zhong)點限制著(zhu)發(fa)球(qiu)(qiu)(qiu)員(yuan)發(fa)球(qiu)(qiu)(qiu)時的(de)(de)(de)(de)站位。