问题 选择题

学习化学时会遇到许多“相等”,下列有关“相等”的说法中错误的是(  )

A.参加化学反应的各物质质量总和与反应后生成的各物质质量总和一定相等

B.中和反应中参加反应的酸和碱的质量一定相等

C.溶液稀释前后溶质的质量一定相等(在稀释时溶质不发生化学变化)

D.化合物中元素化合价的正价总数与负价总数的绝对值相等

答案

A、参加化学反应的各物质质量总和与反应后生成的各物质质量总和一定相等.正确;

B、中和反应中参加反应的酸和碱的质量不一定相等,例如盐酸和氢氧化钠恰好完全反应时的质量比是36.5:40.错误;

C、如果稀释时溶质不发生化学变化,溶液稀释前后溶质的质量一定相等.正确;

D、化合物中元素化合价的正价总数与负价总数的绝对值相等.正确.

故选B.

阅读理解

Riding School:

You can start horse-riding at any age. Choose private or group lessons any weekday between 9 a.m and 8:30 p.m (3:30p.m on Saturday). There are 10 kilometers of tracks and paths for leisurely rides across farmland and open country. You will need a riding hat.

Opening hours: Monday through Friday:9:00a.m—8:30 p.m.

Phone: (412) 396—6754 Fax: (412)396—6752

Sailing Club:

Our Young Sailor’s Course leads to the Stage 1 Sailing qualification.You’ll learn how to sail safely and the course also covers sailing theory and first aid.Have fun with other course members , afterwards in the clubroom.There are 10 weekly two-hour 1essons (Tuesdays 6 p.m.—8 p.m.).   

Opening Hours:Tuesdays:6:00 p.m.—8:00 p.m.

Phone:(412)396—6644    Fax:(412)396—6644

Diving Centre:

Our experienced instructors offer one-month courses in deep-sea diving for beginners. There are two evening lessons a week, in which you learn to breathe underwater and use the equipment safely. You only need swimming costume and towel. Reduced rates for couples.

Opening Hours: Monday and Friday: 6∶30 p. m.—8∶30 p. m.

Phone: (412) 396—6312    Fax: (412) 396—6706

Medical Center:

The staff of the Medical Center aim to provide convenient and comprehensive medical care to students and staff of the university.The center is well equipped and the staff here are trained to deal with a broad range of medical problems.Both female and male doctors as well as nursing staff are available for consultation.Also,all kinds of medicines are sold here and are cheaper for students than other drugstores.

Opening Hours:24 hour from Monday to Sunday

Phone:(412)396—6649  Fax:(412)396—6648

Watersports Club:

We are a two-kilometer length of river for speedboat racing, and water-skiing, A beginners’ course consists of ten 20-minute lessons. You will learn to handle boats safely and confidently, but must be able to swim. The club is in a convenient central position and is open daily from 9 a.m. to 4 p.m. with lessons all through the day.

Opening Hours: Monday through Friday: 9:00a.m. —4:00 p.m.

Phone: (412)396—6899  Fax: (412)396—6890

小题1:If you want to swim and enjoy activities which are fast and a bit dangerous, you should  join _____    .

A.Watersports Club

B.Diving Centre

C.Sailing Club

D.Riding School小题2:If you want to experience a new activity in the countryside in the mornings, you may fax _____         .

A.(412)396-6648

B.(412)396-6754

C.(412)396-6752

D.(412)396-6890小题3:You want to do an activity one evening a week and get a certificate in the end, you can go to  _____  .

A.Watersports Club

B.Diving Center

C.Sailing Club

D.Riding School小题4:Which is NOT the convenience that the Medical Center provides?

A.Good equipment

B.Well trained staff members

C.Various less expensive medicines

D.Nursery for newly-born babies

填空题