öλÔÓéÀֵǼÈë¿ÚÏÂÔØ

9. Astronomers at the Palomar Observatory have discovered a distant supernova explosion, one that they believe is a type previously unknown to science.
A. that they believe is
B. that they believe it to be
C. they believe that it is of
D. they believe that is
E. they believe to be of

1. Ϊʲô²»ÄÜÊÇthat
µ±ÏÈÐдÊ×ö¶¨Óï´Ó¾äµÄ±öÓthat ¿ÉÒÔÊ¡ÂÔ one ( that ) they believe to be ¡­¡­.

2. ´ú´Ê:it ¶àÓà¡£
One that they believe it to be / One that they believe that it is ¡­¡­¡­  
believe ºóÃæÒѾ­ÓÐÂß¼­±öÓï one ,it ¶àÓà

3. ƽÐнṹ£º
A is B¡¡A/B ҪƽÐжԵÈ£¬
´Ë´¦ one(explosion ) is a type previously unknown to science.  Explosion ²»ÄÜÊÇ a type. ¿ÉÒÔÊÇone of a type

4. ´Ê·¨believe X to be Y / believe that ¡­¡­

¹ÛµãÒ»to be±ÈisÔÚ±íʾʱ¼ä·½ÃæÒªºÃ. ÒòΪisÊÇËûÃÇÒ»Ö±¶¼ÕâôÈÏΪ, ʱ¼ä¸ÅÄîÌ«Ã÷È·, È»¶ø, TO BE¾ÍÓÐÄ£ºýÐÔ, ËùÒÔÕâ¸öÌâÄ¿ÀïÍ·OG˵In the context of this sentence, the infinitive to be is more appropriate than the limited present-tense is in referring to an event that occurred long ago but has been discovered only recently.

¹Ûµã¶þ
ÕâÌâżµÄÀí½â±È½Ïµ¥´¿£¬explosion, the one they believe to be of a type.  ¶¨Óï´Ó¾ä£¬
ÏÈÐдʻ¹Ô­µ½¶¨Óï´Ó¾ä½á¹¹ÖоÍÊÇ£º they believe the explosion to be of a type..... 
¸ù¾Ýbelieve µÄÁ½ÖÖÓ÷¨£º
believe that  ..... ºÍbelieve sth to be sth.....ÕâÀ︽ºÍµÚ¶þÖÖÓ÷¨¡£ºÜ×ÔÈ»µÄÅųýÓÃÏÞ¶¨ÐԽṹ£¬£¨°üÀ¨Ã»ÓÐthat, Ö±½ÓÓÃis µÄ½á¹¹¡££©

²»¹ýÓïÑÔÓкܴóµÄÔ¼¶¨Ë׳ɵIJ¿·Ö£¬¼´Ä³Öֽṹ±¾Éí¾Í´øÓÐijÖÖº¬Òå¡£×îºÃµÄ°ì·¨ÊÇ: ¼Çס£¬ÐγÉÏ°¹ßÐÔ˼ά£¬Ö±µ½³ÉΪÓï¸Ð¡£¿´µ½Ä³Öֽṹ¾Í¾õµÃÓ¦¸ÃÊÇÕâ¸öÒâ˼¡£ 
ÏÂÁЄÓÔ~½ÓtoV•r¿‚ÊÇÓñ»„Ó
allege, assume, claim, consider, deem, feel, find, know..., believe, ...
Ëû‚ƒ±íʾÑÔÕ„£¬Ïë·¨»ò°l¬F•r£¬ááÃæ³£½Ó to be »ò to have Vpp

thatÈç¹ûÒýµ¼±öÓï´Ó¾ä, Ò»¶¨²»ÄÜÊ¡ÂÔ.

thatÈç¹ûÒýµ¼¶¨Óï´Ó¾ä: 1. Èç¹ûthatÔÚ´Ó¾äÀï×öÖ÷Óï, ²»ÄÜÊ¡ÂÔ; 2. thatÔÚ´Ó¾äÀï×ö±öÓï, Ê¡ÂÔ.

µ«ÉÏÃæµÄ2ÔÚOGÀïÓз´Àý. 243¾ÍÊÇthat×öºóÃæµÄ±öÓï¶ø²»Ê¡ÂÔµÄ. Õâ²¢²»ÊÇETS×ÔÏàì¶Ü, ¶øÊDz¹³öthat±ÜÃâÆçÒå. ËùÒÔ, ûÓоø¶ÔµÄ¹æÂÉ, Ö»ÓÐÏà¶ÔµÄÕýÈ·, ÒòΪÓïÑÔµÄ÷ÈÁ¦ÔÚÓÚÁé»î