下列情况中，诉讼时效期间为2年的是( )。A．身体受到伤害要求赔偿 B．延付租金

Do you want to live a happier, less stressful(有压力的) life? Try laughing for no reason at all. That’s how millions of people start their day at Laughter(笑声) Clubs around the world and many doctors now think that having a good laugh might be one of the best ways to stay healthy.

The first Laughter Club was started in Mumbai, India, in 1995 by Dr. Madan Kataria.“Young children laugh about 300 times a day. Adults laugh between 7 and 15 times a day,” says Dr. Kataria. “Everyone is naturally good at laughing — it’s the common language. We want people to feel happy with their lives.” There are now more than 500 Laughter Clubs in India and over 1,300 in the world.

Many doctors are also interested in the effects(效果) of laughter on our health. According to a 5-year study at the UCLA School of Medicine in California, with laughing there is less stress in the body. Laughter improves our health against illness by about 40%.

So what happens at a Laughter Club? I went along to my nearest club in South London to find out. I was quite nervous at the beginning of the class, to be honest, I wasn’t interested in laughing with a group of strangers, and I was worried about looking silly. Our laughter teacher told us to clap our hands and say “ho ho ho, ha ha ha” while looking at each other. However, our bodies can’t tell the difference between real laughter and unreal laughter, so they still produce the same healthy effects.

Surprisingly, it works! After ten minutes everybody in the room was laughing for real and some people just couldn’t stop! At the end of the class I was surprised by how relaxed and comfortable I felt. So if you’re under stress, then start laughing. You might be very pleased with the results.

小题1:The first Laughter Club was started in __________.

A．India

B．America

C．Britain

D．China小题2:How many Laughter Clubs are there in the world today?

A．Over 300.

B．Over 500.

C．Over 800.

D．Over 1,300.小题3:How did the writer feel at the beginning of the class?

A．Surprised.

B．Pleased.

C．Nervous.

D．Tired.小题4:When did the people in the club begin to laugh for real?

A．After ten minutes.

B．After ten hours.

C．After ten seconds.

D．After ten days.小题5:The article mainly tells us __________.

A．young children laugh much more often than adults in a day

B．laughing is one of the best ways to stay healthy

C．many doctors are also interested in the effects of laughter on our health

D．real laughter and unreal laughter are both good for health

如图5所示，物块A静止在水平放置的固定木板上，若分别对A施加相互垂直的两个水平拉力F₁和F₂作用时（F₁＜F₂），A将分别沿F₁和F₂的方向匀加速滑动，其受到的滑动摩擦力木小分别为F_f1和F_f2，其加速度大小分别为a₁和a₂；若从静止开始同时对P施加F₁和F₂，其受到的滑动摩擦力大小为F_f3，其加速度大小为a₃，关于以上各物理量之间的关系，判断正确的是（   ）

A．a₃＝a₁＝a₂

B．a₃＞a₂＞a₁

C．F_f3＞F_f1＝F_f2

D．F_f1＝F_f2＞F_f3

按照我国中小学内部领导体制对机构设置及其隶属关系的规定，与党支部书记属于同一职级的是（）

A.校长

B.教研组长

C.政教主任

D.总务处长

洪水期间，临河水深、水面宽，若遇大风，易形成（）。

A.急流

B.主流

C.冲击力大的风浪

D.环流

分子生物学信息数据库主要有哪4大类？