1．I see an apple. It's on the watermelon.

我看见一个苹果。它在西瓜上。

2．I see a banana. It's in the box.

我看见一根香蕉。它在盒子里。

3．A：Where is the ball?

A：球在哪里？

B：It's under the desk.

B：它在书桌下面。