按要求转换下列句型，每空限填一词。
46、The English problem is too difficult for him to work out.(改为复合句)。
The English problem is ___ difficult he can’t work it out.
47、The surfers both won first price in the city surfing competition(改为否定句)
____ ____ the surfers won first price in the city surfing competition.
48、I think the fastest way to travel is by plane.（改为特殊疑问句）
___do you think___ the fastest way to travel?
49、Mrs. Zhang showed us a picture of the feathered dinosaur(改被动语态)。
We ____ _____ a picture of the feathered dinosaur by Mrs zhang.
50、Bob had no teacher, but he becarne Chinese well at his young age.(改为同义句)。
Bob_____ _____ Chinese when he was young.