Last week's talent show was a great success.（改为同义句）改句：The talent show () () ()was a great success.

Last week's talent show was a great success.（改为同义句）改句：The talent show () () ()was a great success.
Last week's talent show was a great success.（改为同义句）
改句：The talent show () () ()was a great success.

Last week's talent show was a great success.（改为同义句）改句：The talent show () () ()was a great success.
答案应该是


The talent show ( of last week )was a great success.

名词的所有格,经常可以用 ...of 来代替

held last week

The talent show (in) (last) (week)was a great success.