What do you do if you're stranded（处于困境的）on a lonely island? Surely you need to find a way to get in touch with the outside world. Your best chance of doing this is to draw the attention of a passing plane.

　　Body signals（信号）

　　Pilots from different countries understand body signals if they have the correct training. When you wave your arms up and down in a straight line, it means "yes". When you point downwards and swing your arm from side to side, it means "no". If you want the pilot to know that it's safe to land, push your hands out in front of you and bend（弯曲）your knees. If you want to say that it's not safe to land, put your arms in the air and move them to one side.

　　Smoke signals

　　The smoke from a fire can be seen from far away, so it's a good way to draw attention. If the weather is dry, it isn't hard to start a fire. Remember, however, that fires can be very dangerous if they get out of control. Never light a fire unless you're sure that it can't spread. If the ground is dark, light smoke can be seen more easily. Green grass and leaves produce light smoke.

　　Ground-to-air signals

　　It's a good idea to build some signals, too. Use large pieces of wood to make the symbols(标记). If you can't find any wood, use earth. Some useful symbols are:

　　F "I need food and water."

　　II "I need medicine."

　　I "I am badly hurt."

　　X" I am unable to move from here."

　　Pilots' replies

　　If the pilot lowers the plane's wings from side to side, this means "message received and understood". (At night, the pilot flashes the plane's green lights.) If the pilots flies the plane in a clockwise circle, this means "message received but not understood".(At night, the pilot flashes the plane's red lights.)

However, there is no signal which means "message not received". Why not?

1. Which picture means "it's not safe land"?

2. What can we learn from the passage?

　　A. Swinging your arm from side to side means "yes".

　　B. If the ground is dark, light smoke can't be seen.

　　C. If you need some medicine, make a symbol "II".

　　D. The pilots make replies with a blue light at night.

　　3. What is the passage mainly about?

　　A. The explanation of building signals on an island.

　　B. The importance of making signals on an island.

　　C. Ways of sending out signals on a lonely island.

D. Ways of receiving signals from a lonely island

 Laboratory　work　is　your　chance　to　learn　science　firsthand.　It　can　be　fun　but　you　must　be　careful　to　prevent　injury.　Listen　closely　when　your　teacher　reads　and　explains　the　rules　before　your　first　lab　lesson.
LABORATORYRULES
Throughout　the　lesson
·Do　not　enter　the　science　lab　without　the　teacher’s　permission.·No　food　or　drinks　are　to　be　alowed　in　the　science　lab.
Before　the　Experiment
·Read　al　instructions　carefuly　before　every　experiment.
·Prepare　al　apparatus（仪器）and　arrange　them　so　that　you　wil　not　knock　them　over　while　doing　the　experiment.
During　the　Experiment
·If　you　are　unsure　of　how　to　use　any　apparatus　or　how　to　operate,　ask　your　teacher　for　help.·Never　smel　or　taste　chemicals　unless　your　teacher　gives　permission.
After　the　Experiment
·Wash　al　apparatus　after　use　and　return　them　to　the　places　where　they　were.
·Throw　waste　materials　in　proper　waste　baskets.　　　　First　Aid　　　　
·Report　al　accidents　to　your　teacher　immediately.
·If　you　spil（ 溅 出 ）any　chemicals　onto　your　body　or　clothing,　wash　with　plenty　of　water　and　report　to　your　teacher.
【小题1】　Your　teacher　wil　probably　tel　you　the　rules　above　_____　the　first　lab　lesson.

A．taste　the　chemicals　first

B．clean　al　the　apparatus

C．read　al　instructions　carefuly

D．report　al　the　accidents　to　the　teacher

A．bring　food　into　the　lab
B．enter　the　lab　anytime
C．smel　chemicals　as　you　like	D．learn　science　directly　in　the　lab

A．Before　the　Experiment

B．First　Aid

C．During　the　Experiment

D．After　the　Experiment

On June 26, 2000, two scientists, called Francis Collins and Craig Venter, told the world that they could now read the whole “map” of the human body: DNA. DNA is something that everybody has, and it tells the body what to do. DNA is the reason that we look like our mother and father, because we get some of their DNA to make our own.

People have been trying to understand the human body for a long time. In 1860, Gregor Mendel discovered a special reason why we look the same as other people in our family. It is because of small things named “genes” in our body. In 1953, James Watson and Francis Crick made another discovery and found out that those small parts are real messages written in the DNA with a special language.

　　In 1961, Marshall Nirenberg and Johann Matthaei found a message in DNA showing how DNA tells the cell (细胞) to build its parts. Scientists have now found all the words in the DNA map, but we still do not understand what they all do. By understanding what just one “word” means, we can help save more people from several illnesses.

　　Most people hope that this will help make better medicine and help sick people. Other people worry that when people begin to know more words and find out lots of other information, we might use it in a wrong way, just to make people more attractive, or stop sick people from getting jobs. Man would have to meet a lot of trouble if DNA technology (技术) wasn’t limited (限制) in use.

1.When did we first know why we look like other people in our family?

A. In 1860. B. In 1953. C. In 1961. D. In 2000.

2.What did the two scientists first discover in 1961?

A. The “map” of DNA. B. A new illness.

C. The language of DNA. D. A message of DNA.

3.What can we do if we understand some “words” of the language inside the body?

A. Make people get new jobs.

B. Make medicine for illnesses.

C. Make maps of human.

D. Make people less attractive.

4.What do people think about this work?

A. It can cause good or bad results.

B. It can cause only good results.

C. It can cause good results but won’t work.

D. It can cause only bad results.

 Laboratory　work　is　your　chance　to　learn　science　firsthand.　It　can　be　fun　but　you　must　be　careful　to　prevent　injury.　Listen　closely　when　your　teacher　reads　and　explains　the　rules　before　your　first　lab　lesson.

    LABORATORYRULES

    Throughout　the　lesson

    ·Do　not　enter　the　science　lab　without　the　teacher’s　permission.·No　food　or　drinks　are　to　be　alowed　in　the　science　lab.

    Before　the　Experiment

    ·Read　al　instructions　carefuly　before　every　experiment.

    ·Prepare　al　apparatus（仪器）and　arrange　them　so　that　you　wil　not　knock　them　over　while　doing　the　experiment.

    During　the　Experiment

    ·If　you　are　unsure　of　how　to　use　any　apparatus　or　how　to　operate,　ask　your　teacher　for　help.·Never　smel　or　taste　chemicals　unless　your　teacher　gives　permission.

    After　the　Experiment

    ·Wash　al　apparatus　after　use　and　return　them　to　the　places　where　they　were.

    ·Throw　waste　materials　in　proper　waste　baskets.　　　　First　Aid　　　　

    ·Report　al　accidents　to　your　teacher　immediately.

    ·If　you　spil（ 溅 出 ）any　chemicals　onto　your　body　or　clothing,　wash　with　plenty　of　water　and　report　to　your　teacher.

   1.　Your　teacher　wil　probably　tel　you　the　rules　above　_____　the　first　lab　lesson.

    A.　before　　　　　B.　since　　　　C.　during　　　　D.　after

2.　Before　every　experiment,　you　should　_____.

    A.　taste　the　chemicals　first

    B.　clean　al　the　apparatus

    C.　read　al　instructions　carefuly

    D.　report　al　the　accidents　to　the　teacher

  3.　When　you　are　not　sure　how　to　use　al　apparatus,　_____.

    A.　try　them　on　your　own

    B.　read　the　rules　carefuly

    C.　ask　your　teacher　for　help

    d.　put　them　back

 4.　It　is　clear　that　you　can　_____.

    A.　 bring　food　into　the　lab

    B.　enter　the　lab　anytime

    C.　smel　chemicals　as　you　like

    D.　learn　science　directly　in　the　lab

    5.　If　you　get　chemicals　on　the　clothing,　you　can　find　ways　to　solve　it　in　the　part　_____.

    A.　Before　the　Experiment

    B.　First　Aid

    C.　During　the　Experiment

    D.　After　the　Experiment

The human body is a living machine, and, like all machines, it needs “fuel” to supply it with energy. This is provided by the food we eat. But how much do we need to stay healthy?
The energy value of food is usually measured in calories(卡). A calorie is the amount of heat required to raise the temperature of 1 kg of water by 1℃. The number of calories people need per day is different, as the picture shows. Also, the number of calories you use at any one moment normally depends on the activity you are in. For example, you need more calories for standing than for sitting, more for running than for walking, and so on.
The energy in food is in the form of three kinds of chemical materials—carbohydrate（碳水化合物）, protein（蛋白质） and fat. Carbohydrate provides 3.8 Cal /gm of the energy, protein 4.0 Cal/gm, and fat 8.8 Cal/gm. Each food contains different amounts of these materials, as the round pictures show.
(P= protein      C= carbohydrate    F=fat)
【小题1】How many calories are needed to raise the temperature of 5kg of water from 35℃ to 90℃?