There's (a picture)on the wall.(对括号部分提问）
It's under the boy's desk.（改为一般疑问句）
Ican see (many) flowers in the vase.(对括号部分提问）
The books are (in his bag).(对括号部分提问）
We can see (some stamps) in the stamp album.(对括号部分提问）
There is (a guitar) on tile wall.(对括号部分提问)