The little girl is not tall enough to reach the book on the shelf(改為同義句）
the girl is(too shot ) to reach the book on the shelf.
( 樓主是不是給多了一個空?因為not adj.+enough to do sth = too +adj.+ to do sth )
也可以改為從句：
The girl is ( so short that she can't )reach the book on the shelf .
加油!不明白再問!我也不知道，試卷上有三個空，要兩個空我也做出來了那就是題目有錯了。