答：網球場是(shi)一塊(kuai)由邊(bian)線(xian)(xian)(xian)(xian)、端(duan)(duan)(duan)(duan)線(xian)(xian)(xian)(xian)、中(zhong)線(xian)(xian)(xian)(xian)、發(fa)(fa)(fa)(fa)球(qiu)(qiu)(qiu)(qiu)線(xian)(xian)(xian)(xian)和中(zhong)點(dian)(dian)組成(cheng)(cheng)的(de)(de)(de)長(chang)(chang)(chang)方形(xing)的(de)(de)(de)場(chang)地。球(qiu)(qiu)(qiu)(qiu)場(chang)兩邊(bian)的(de)(de)(de)界(jie)線(xian)(xian)(xian)(xian)叫邊(bian)線(xian)(xian)(xian)(xian)，邊(bian)線(xian)(xian)(xian)(xian)長(chang)(chang)(chang)23.77米(mi)(78英(ying)尺)。在距球(qiu)(qiu)(qiu)(qiu)網(wang)(wang)兩側6.40米(mi)(21英(ying)尺)長(chang)(chang)(chang)的(de)(de)(de)四(si)條(tiao)單打(da)邊(bian)線(xian)(xian)(xian)(xian)除起(qi)著判(pan)定單打(da)擊。球(qiu)(qiu)(qiu)(qiu)是(shi)否(fou)出(chu)(chu)(chu)界(jie)(邊(bian)線(xian)(xian)(xian)(xian)出(chu)(chu)(chu)界(jie))的(de)(de)(de)作(zuo)(zuo)用外，還起(qi)著判(pan)定發(fa)(fa)(fa)(fa)球(qiu)(qiu)(qiu)(qiu)是(shi)否(fou)界(jie)外(發(fa)(fa)(fa)(fa)球(qiu)(qiu)(qiu)(qiu)邊(bian)線(xian)(xian)(xian)(xian)出(chu)(chu)(chu)界(jie))的(de)(de)(de)作(zuo)(zuo)用。球(qiu)(qiu)(qiu)(qiu)場(chang)兩端(duan)(duan)(duan)(duan)的(de)(de)(de)界(jie)線(xian)(xian)(xian)(xian)叫端(duan)(duan)(duan)(duan)線(xian)(xian)(xian)(xian)。單打(da)端(duan)(duan)(duan)(duan)線(xian)(xian)(xian)(xian)長(chang)(chang)(chang)8.23米(mi)(27英(ying)尺)(圖1)。雙(shuang)打(da)端(duan)(duan)(duan)(duan)線(xian)(xian)(xian)(xian)長(chang)(chang)(chang)10.97米(mi)(36英(ying)尺)(圖2)，比(bi)單打(da)場(chang)地海邊(bian)多(duo)1.37米(mi)(4 1/2英(ying)尺)。端(duan)(duan)(duan)(duan)線(xian)(xian)(xian)(xian)除起(qi)著判(pan)定擊球(qiu)(qiu)(qiu)(qiu)是(shi)否(fou)界(jie)外(端(duan)(duan)(duan)(duan)線(xian)(xian)(xian)(xian)出(chu)(chu)(chu)界(jie))的(de)(de)(de)作(zuo)(zuo)用外，還起(qi)著判(pan)定發(fa)(fa)(fa)(fa)球(qiu)(qiu)(qiu)(qiu)員(yuan)發(fa)(fa)(fa)(fa)球(qiu)(qiu)(qiu)(qiu)時(shi)是(shi)否(fou)踏線(xian)(xian)(xian)(xian)違例(腳誤)的(de)(de)(de)作(zuo)(zuo)用。在球(qiu)(qiu)(qiu)(qiu)網(wang)(wang)兩側6.40米(mi)(2l英(ying)尺)處的(de)(de)(de)場(chang)內(nei)(單打(da)球(qiu)(qiu)(qiu)(qiu)場(chang)場(chang)內(nei))各(ge)畫一條(tiao)與(yu)(yu)球(qiu)(qiu)(qiu)(qiu)網(wang)(wang)平行的(de)(de)(de)橫(heng)線(xian)(xian)(xian)(xian)叫做(zuo)發(fa)(fa)(fa)(fa)球(qiu)(qiu)(qiu)(qiu)線(xian)(xian)(xian)(xian)。聯結(jie)兩發(fa)(fa)(fa)(fa)球(qiu)(qiu)(qiu)(qiu)線(xian)(xian)(xian)(xian)的(de)(de)(de)中(zhong)點(dian)(dian)，畫一條(tiao)與(yu)(yu)邊(bian)線(xian)(xian)(xian)(xian)平行的(de)(de)(de)線(xian)(xian)(xian)(xian)叫做(zuo)中(zhong)線(xian)(xian)(xian)(xian)，中(zhong)線(xian)(xian)(xian)(xian)與(yu)(yu)球(qiu)(qiu)(qiu)(qiu)網(wang)(wang)成(cheng)(cheng)“十”字形(xing)，將發(fa)(fa)(fa)(fa)球(qiu)(qiu)(qiu)(qiu)線(xian)(xian)(xian)(xian)與(yu)(yu)邊(bian)線(xian)(xian)(xian)(xian)間(jian)的(de)(de)(de)地面分(fen)成(cheng)(cheng)四(si)個(ge)相等(deng)的(de)(de)(de)區(qu)(qu)域，這個(ge)區(qu)(qu)域叫做(zuo)發(fa)(fa)(fa)(fa)球(qiu)(qiu)(qiu)(qiu)區(qu)(qu)。發(fa)(fa)(fa)(fa)球(qiu)(qiu)(qiu)(qiu)員(yuan)只有(you)將球(qiu)(qiu)(qiu)(qiu)發(fa)(fa)(fa)(fa)在規定的(de)(de)(de)發(fa)(fa)(fa)(fa)球(qiu)(qiu)(qiu)(qiu)區(qu)(qu)內(nei)才算(suan)合法發(fa)(fa)(fa)(fa)球(qiu)(qiu)(qiu)(qiu)。在端(duan)(duan)(duan)(duan)線(xian)(xian)(xian)(xian)的(de)(de)(de)中(zhong)心，向場(chang)內(nei)畫一條(tiao)10厘米(mi)(4英(ying)寸)長(chang)(chang)(chang)、5厘米(mi)(2英(ying)寸)寬的(de)(de)(de)垂(chui)直于端(duan)(duan)(duan)(duan)線(xian)(xian)(xian)(xian)的(de)(de)(de)短線(xian)(xian)(xian)(xian)叫做(zuo)中(zhong)點(dian)(dian)。中(zhong)點(dian)(dian)將端(duan)(duan)(duan)(duan)線(xian)(xian)(xian)(xian)分(fen)成(cheng)(cheng)相等(deng)的(de)(de)(de)兩部分(fen)。中(zhong)點(dian)(dian)限制著發(fa)(fa)(fa)(fa)球(qiu)(qiu)(qiu)(qiu)員(yuan)發(fa)(fa)(fa)(fa)球(qiu)(qiu)(qiu)(qiu)時(shi)的(de)(de)(de)站位。