阅读理解。
    Imagine the first days in a new time zone. Slow to respond to the 1, your body clock is confused. You’re sleepy all day, but when it's time for bed, you can hardly fall asleep. Obviously you are2jet lag（时差反应）.

    Travelers have traditionally fought this 3 with sleeping pills or alcohol. There are actually healthier ways that can work just as 4.

    For example, the moment you get on the airplane, start 5 your biological block to the destination's time. If it's daytime in your destination, try to stay 6 . Walking around the cabin（客舱） can be of help. When it’s nighttime, try to sleep. In that case, eat before the flight, 7 an empty stomach will prevent you from sleeping. These tips will help you start a new 8of sleep and wakefulness.

    蚕乡小镇，四周河浜（bāng）萦绕，交通工具只有小船，它的早晨是木船悠闲的摇橹声唤醒的。

    小镇的早晨是恬静的。淡淡的霞光下，宽宽的河面闪烁着一片斑斓的银鳞，河水净得透明。沿街的河边停满了各式各样的小船，一只挨着一只，好像一座水上浮桥。两座拱形的石桥遥遥相对，不时有一片片小舟从半月形的桥洞中悄悄钻出来，又在河上轻轻飘过，船驶远了。河面上荡漾着船工愉快粗犷的小调和从大街上飘来的游丝般迷离的叫卖声。

    小镇上的早晨又是热闹的。走在大街上，仿佛置身在一个欢乐的旋涡。沿街摆满了各种土特产。刚从地里割下来的青菜还带着露珠；刚从河里捕上来的鱼、虾又蹦又跳；还有小羊羔、长毛兔……真叫人目不暇接，留恋不止。

    小镇的早晨更是紧张的。大街两旁，不少经营的个体户早早地开张了。河对岸急急地移动着一条彩色的人流，那是去上班的农家姑娘。镇上盛产蚕茧，今年他们办起了自己的丝织厂，小镇在变化。

    多美的小镇的早晨呀！它的早晨就这样在木船悠闲的摇橹声中醒来了。

下列有关对人体消化系统的描述中，不正确的是（　　）