�。�1）賓語(yǔ)從句中主句和從句的時(shí)態(tài)保持一致，但如果從句中表示提示的是客觀現(xiàn)象，雖然主句是過(guò)去時(shí)態(tài)，從句仍用一般現(xiàn)在時(shí)。如：
　　Hello,I didn’t know you were in London. How long have you been here?
　　The teacher told us that light travels at a very high speed.
　�。�2）主語(yǔ)從句作主語(yǔ)相當(dāng)于單數(shù)第三人稱(chēng)作主語(yǔ)，謂語(yǔ)動(dòng)詞用單數(shù)，如果由and 連接兩個(gè)或兩個(gè)以上的主語(yǔ)從句作主語(yǔ)時(shí)，謂語(yǔ)動(dòng)詞用復(fù)數(shù)；由兩個(gè)或多個(gè)連接詞引導(dǎo)一個(gè)主語(yǔ)從句，謂語(yǔ)動(dòng)詞用單數(shù)。如：
　　When the meeting will begin has not been decided yet.
　　When they will start and where they go have not been decided yet.
　　When and where the meeting will begin has not been decided.

本文來(lái)自：逍遙右腦記憶 http://portlandfoamroofing.com/gaozhong/868895.html

相關(guān)閱讀：�？荚~的語(yǔ)法與用法：after

閻楀牊娼堟竟鐗堟閿涙碍婀伴弬鍥у敶鐎瑰湱鏁辨禍鎺曚粓缂冩垹鏁ら幋鐤殰閸欐垼纭€閻氼噯绱濈拠銉︽瀮鐟欏倻鍋ｆ禒鍛敩鐞涖劋缍旈懓鍛拱娴滄亽鈧倹婀扮粩娆庣矌閹绘劒绶垫穱鈩冧紖鐎涙ê鍋嶇粚娲？閺堝秴濮熼敍灞肩瑝閹枫儲婀侀幍鈧張澶嬫綀閿涘奔绗夐幍鎸庡閻╃ǹ鍙у▔鏇炵伐鐠愶絼鎹㈤妴鍌氼洤閸欐垹骞囬張顒傜彲閺堝绉圭€氬本濡辩悮顓濋暅閺夛拷/鏉╂繃纭舵潻婵婎潐閻ㄥ嫬鍞寸€圭櫢绱濈拠宄板絺闁線鍋栨禒鎯板殾 bjb@jiyifa.com 娑撶偓濮ら敍灞肩缂佸繑鐓＄€圭儑绱濋張顒傜彲鐏忓棛鐝涢崚璇插灩闂勩們鈧拷