不经胰蛋白酶激活的胰酶是（） A.糜蛋白酶 B.脂肪酶 C.强力蛋白酶 D.激肽酶

用石墨做电极电①稀H₂SO₄  ②K₂SO₄溶液  ③CuCl₂溶液  ④CuSO₄ 溶液 ⑤KOH溶液．

（1）阴阳极都有气体产生，且体积比（相同条件下）为2：1的是______（填序号，下同），其阳极的电极反应式都是______，阴极的电极反应式都是______，总反应的化学方程式是______．

（2）阴极．阳极都有气体产生，其中溶液的pH变小的是______，pH变大的是______．

（3）一个电极析出金属，一个电极析出气体，且溶液pH明显减小的是______，其总反应的化学方程式是______．

People like different kinds of vacations. Some go camping. They swim, fish, cook over a fire and sleep outside. Others like to stay at a hotel in an exciting city. They go shopping all day and go dancing all night. Or maybe they go sightseeing to places such as Disneyland, the Tai Mahan or the Louver.

Some people are bored with sightseeing trips. They don’t want to be “tourists”. They want to have an adventure--a surprising and exciting trip. They want to learn something and maybe help people too. How can they do this? Some travel companies and environmental groups are planning special adventures. Sometimes these trips are difficult and full of hardships, but they’re a lot of fun. One organization, Earth watch, sends small groups of volunteers to different parts of the world. Some volunteers spend two weeks and study the environment. Others work with animals. Others learn about people of the past.

Would you like an adventure in the Far North? A team of volunteers is leaving from Mormons, Russia. The leader of this trip is a professor from Alaska. He’s worried about chemicals from factories. He and the volunteers will study this pollution in the environment. If you like exercise and cold weather, this is a good trip for you. Volunteers need ski sixteen kilometers every day.

Do you enjoy ocean animals? You can spend two to four weeks in Hawaii. There, you can teach language to dolphins. Dolphins can follow orders such as “Bring me the large ball.” They also understand opposites. How much more can they understand? It will be exciting to learn about these intelligent animals. Another study trip goes to Washington State and follows orcas. We call orcas “killer Whale”, but they’re really dolphins—the largest kind of dolphin. This beautiful animal travels together in family groups. They move through the ocean with their mothers, grandmothers and great-grandmothers. Ocean pollution is chasing their lives. Earth watch is studying how this happens.

Are you interested in history? Then Greece is the place for your adventure. Thirty-five hundred years ago a volcano exploded there, on Santorum. This explosion was more terrible than Karate or Mount Saint Helens. But today we know a lot about the way of life of the people from that time. There are houses, kitchens, and paintings as interesting as those in Pompeii. Today teams of volunteers are learning more about people from the past.

Do you want a very different vacation? Do you want to travel far, work hard and learn a lot? Then an Earth watch vacation is for you.

小题1:The Tai Mahan may be _______.

A．a shopping center

B．a hotel　

C．a dancing hall

D．a place of interest小题2:From the passage, on an adventure trip, people ______.

A．may not spend much time on sightseeing

B．won’t meet some difficulties or hardships

C．can’t enjoy them

D．can’t learn something小题3:If you want to learn something about people of the past, you can _______.

A．join the team to Hawaii

B．join the team to the Far North

C．join the team to Washington

D．join the team to Greece小题4:The word intelligent in paragraph 4 means _______.

A．exciting

B．beautiful

C．large

D．clever小题5:Which of the following is false?

A．Some people find sightseeing trips boring.

B．Earth watch is planning all these special adventures.

C．The number of orcas is decreasing.

D．3 volcano explosions in all broke out 3, 500 years ago in Greece.

大气按组成成分可分为（）、（）、（）。

系统误差是在对同一被测量的多次测量过程中，保持（）或以（）的方式变化的测量误差分量。

备用电源自动投入在什么情况下动作？