Rewrite the following sentences as required (根据所给要求，改写下列句子。每空格限填一词)
David left Shanghai for London to further his study last year. (改为否定句)
David ________ ________ Shanghai for London to further his study last year.
Teenagers should learn how they should take care of themselves. (改为简单句)
Teenagers should learn how                     for themselves.
Sandy has been in the Science Club since eight months ago.  (对划线部分提问)
________ ________ has Sandy been in the Science Club?
Of all the tourist attractions, Martha likes the Great Wall best. (保持句意基本不变)
Martha likes the Great Wall ________ ________ any other tourist attraction.
Lily threw away the old coats because she thought they were out of date. (改为被动语态）
The old coats ________ _______ away by Lily because she thought they were out of date.
The little boy never has lunch at school.（改为反意疑问句）
The little boy never has lunch at school, _________ _________?
Will Karen take part in Lucy’s birthday party? Mr. Smith asked me. (改为宾语从句)
Mr. Smith asked me __________ Karen ________ take part in Lucy’s birthday party.