1.The river is about 10 meters deep.（對劃線部分提問） —————————— ___ ___ is the river?
1.The river is about 10 meters deep.（對劃線部分提問）
——————————
___ ___ is the river?
2.This is a tree. He planted the tree 3 years ago.（合并為一個含有特定語從句的復合句）
This is the tree ___ he planted 3 yeats ago.