句型转换（本题共5小题，每小题1分，计5分）
按要求完成下面各句。每空一词。
They got a letter from their son twice a month . (改为同义句)
They ________  ________ their son twice a month .
She did very well in her work. (变否定句)
She _________  _________very well in her work .
Tom never writes to his pen pal. (改为反意疑问句)
Tom never writes to his pen pal every month , ________  ________?
They built a new bridge in 2007．(改为被动语态)
A new bridge ________  ________ by them in 2007.
Little Jim is only five years old. He can’t make model planes by himself. （合并为一句)
Little Jim is _________ young __________ make model planes by himself.