Insert the special cleaning thread between your teeth and pull it gently up and down.

把這條特制的棉線嵌在牙齒間,然后輕輕地上下移動。

If you can insert your hand between the back of the chair and the wall, you may be able to reach the letter that fell down there.

如果你能把你的手伸進靠墻的那把椅子后面,或許你能夠著掉在那兒的那封信。