⒊ ⑴ is well known to us all , the earth goes around the sun .
⑵ is well known to us all that the earth goes around the sun .
A. That B. As C. It D. Which
析：⑴ B ⑵ C 。句 ⑴ 是由 as 的非限制性定语从句，代替后面整个句子。句 ⑵ 是it 引导的主语从句。 it 是形式主语，真正的主语是 that 引导的从句。
⒋ ⑴ I have two sisters , are doctors .
⑵ I have two sisters , and are doctors .
A. both of them B. both of whom C. neither of them D. each of whom
析： ⑴ B ⑵ A 。句 ⑴ 是定语从句， 因从句中动词是 are ，所以只能选 B ，而不能选 D 。句 ⑵ 因有并列连词 and ，所以是并列句，再根据主谓一致原则，只能选 A 。
⒌ ⑴ I\'ll never forget the days I spent with him .
⑵ I\'ll never forget the day I was born .
A. when B. that C. on which D. both A and C
析：⑴ B ⑵ D 。 句 ⑴、⑵都是定语从句，句 ⑴ 中 that 在从句中作 spent 的宾语，还可用 which ，也可省略。句 ⑵ when 在定语从句作状语，也等于 on which ，故选 D 。
⒍ ⑴ Was it Octorber 1 , 1949 the People\'s Republic of China was founded ?
⑵ Was it on October 1, 1949 the People\'s Repulice of China was founded ?
A. in which B. on that C. that D. when
析：⑴ D ⑵ C 句 ⑴ 是 when 引导的定语从句，句 ⑵ 是强调句，特别注意句 ⑵ 中 Octorber 之前的 on 。
⒎ ⑴ He is the only one of the students who the accident .
⑵ He is one of the students who the accident .
A. knows B. know C. had known D. known
析：⑴ A ⑵ B 句⑴、⑵都是定语从句，在“ the ( only ) one of + 复数名词 + 定语从句”结构中，先行词是 one ，而不是复数名词，故从句中谓语动词用单数。但是在“ one of + 复数名词 + 定语从句”句型中，先行词是复数名词，故从句中谓语动词用复数。
⒏ ⑴ Do you know the fact the sun is brighter than the moon ?
⑵ Do you underswtand the easiest fact he explained to you just now ?
A. that B. which C. the one D. as
析：⑴ A ⑵ A 句⑴是 that 引导的同位语从句， that 在从句中不作任何成分，不能省略。句 ⑵ 是 that 引导的定语从句， that 在从句中作 explain 的宾语，因先行词 fact 之前有最高级限制 easiest ，故只能用 that ，不可用 which 。
⒐ ⑴ This is the best reason he could give at the meeting .
⑵ This is the reason he didn\'t go to school this morning .
A. why B. that C. which D. because
析：⑴ B ⑵ A 。 句 ⑴ 是 that 引导的定语从句，that 在从句中作 give 的宾语，因先行词 reason 之前有 best 修饰，故只能用 that 。句 ⑵ 是 why 引导的定语从句，相当于 for which 。
【创新园地】
你是李华，申请到一家外资企业工作。对方要求你用英语写一篇短文，介绍自己的基本情况。短文必须包括下列全部内容。
1. 姓名: 李华 出生年月 : 1977年2月 出生地 : 辽宁大连
2. 学历 :1988-1990光明小学 ; 1990-1996年大连市第六小学
3. 所学主要课程 : 语文、数学、英语、物理、化学、电脑
4. 特长 : 英语、电脑（去年在全校电脑竞赛中获得第一名）