(教材P42)They are mainly for goods and people trading along the river.

　　它们主要是用来运输货物的，乘客多是沿江做生意的人。

　　(1)trade with... 与......做生意

　　trade in 做......生意

　　(2)trade...for... 用......交换/换取......

　　①The two countries trade with each other in agricultural produce.

　　这两个国家在农产品方面有贸易往来。

　　②He traded his pen for a knife with me yesterday.

　　昨天他用钢笔跟我换了一把小刀。

　　 narrow vt.&vi.(使)变窄；(使)缩小adj.狭窄的

　　(教材P42)The gorge narrows to 350 feet as the river rushes through the two­mile­high mountains.

　　当急流穿过两英里高的峡谷时，峡谷变窄了，只有350英尺。

　　(1)narrow...to... 把......局限在......之内

　　(2)have a narrow escape 九死一生

　　narrow victory/defeat 险胜/勉强击败

　　(3)narrowly adv. 勉强地；差一点儿；狭隘地

　　①She narrowed her life to a certain circle of friends.

　　她把她的生活局限在一个特定的朋友圈中。

　　②You were lucky to have a narrow escape from being drowned.

　　＝ You were lucky to narrowly (narrow)escape from being drowned.

　　你侥幸没有溺死，真是幸运。

　　 at least至少

　　(教材P42)"Oh，well，"my friend said，"at least we have two more left."

　　我朋友说："喔，至少我们还能看见另外两个峡谷。"

①He should at least have come to say good­bye.