A. which                                 B. them
C. what                                   D. that
答案选A，none of them were carried out in their work 是非限制性定语从句，注意与上例比较句中多了一个助动词were。
(3) They put forward a lot of plans at the meeting, but none of _______ were carried out in their work.
A. which                                   B. them
C. what                                     D. that
答案选B，由于两句之间增加了一个并列连词but，使得该句成了一个并列句。

■ On Sundays there were a lot of children playing in the park, _______ parents seated together joking.
A. their                                      B. whose
C. which                                   D. that
【易错】容易误选B，认为这是非限制性定语从句。
【分析】最佳答案是A。与上面一题相似，their parents seated together joking 不是非限制性定语从句，而是一个独立主格结构，因为空格后的动词 seated 不是谓语，而是一个过去分词，因为 seat 作动词用时，是及物动词。比较以下相似题：
(1) On Sundays there were a lot of children playing in the park, _______ parents were seated together joking.
A. their                                     B. whose
C. which                                   D. that
选B。whose parents were seated together joking 为非限制性定语从句，因为其后有完整的谓语 were seated。
(2) On Sundays there were a lot of children playing in the park, and _______ parents were seated together joking.
A. their                                      B. whose
C. which                                    D. that
选A。因为句中有并列连词and，整个句子为并列句。
(3) On Sundays there were a lot of children playing in the park, _______ parents sitting together joking.
A. their                                       B. whose
C. which                                     D. that
选A。their parents sitting together joking 为独立主格结构。
(4) On Sundays there were a lot of children playing in the park, _______ parents sat together joking.
A. their                                        B. whose
C. which                                      D. that
选B。whose parents sat together joking 为非限制性定语从句，因为句中有完整的谓语 sat。
(5) On Sundays there were a lot of children playing in the park, _______ parents were sitting together joking.
A. their                                       B. whose
C. which                                    D. that
选B。whose parents were sitting together joking 为非限制性定语从句，因为句中有完整的谓语 were sitting。
■ If the man is only interested in your looks, _____ just shows how shallow he is.
A. as                                           B. which
C. what                                       D. that
【易错】容易误选A或B，误这是非限制性定语从句。
【分析】正确答案为D，注意逗号前是一个条件状语从句，逗号后是该状语从句的主句，that 在此代表前文所述的情况，用作主句的主语。类似地，下面几道题也选 that，而不选 which：
(1) If you promise to go with us, _____ will be OK.
A. as                                         B. which
C. and it                                    D. that
(2) If you want a double room, _____ will cost another ￡15.
A. as                                         B. which
C. what                                     D. that
(3) Whether you go or not, _______ is quite all right with me.
A. that                                       B. which
C. and it                                    D. so
(4) When I say two hours, _____ includes time for eating.
A. as                                         B. which