引起营养不良最常见的原因是()A．先天不足 B．疾病影响 C．长期发热 D．长期腹泻

．—Are you sure of this evening’s performance, Kate?   

—______. I’m well prepared.

A．I hope so.

B．It’s hard to say.

C．Sure, I am.

D．I’m afraid not.

Dogs can be worried and pessimistic just like people, researchers report in a new study in Current Biology. And they aren’t talking about basset hounds (短脚猎狗): those dogs just look as if they expect the worst.

What the scientists say is that dogs that exhibit anxiety when left home alone by their owners may have bigger problems — they may be in a permanent bad mood.

This pessimistic outlook may not otherwise be easily apparent in a dog’s other characteristics, like running speed or learning ability, the study reports.

Dogs are similar to humans in the role that emotional state plays in decision making, said Michael Mendel, a veterinary scientist at the University of Bristol and the study’s lead author. The study’s researchers looked at 24 dogs in shelters in Britain.

They placed the dogs in isolated settings and observed their reactions — many barked, jumped on furniture and scratched at the door.

Then they placed bowls in two rooms. One bowl contained food, while another was empty. After training the dogs to understand that bowls can sometimes be empty, and sometimes full, they began to place bowls in ambiguous locations.

Dogs that quickly raced to the locations were more optimistic, and in search of food. Those that did not were deemed pessimistic.

The more separation anxiety a dog expressed while in isolation, the more likely the dog was to have a pessimistic reaction, the researchers found.

The study carries an important message for dog owners, Dr. Mendel said.

Dogs that express serious anxiety when alone may need treatment, as it could be a sign of unhappiness and instability.

小题1:This passage can be classified as _________.

A．an advertisement

B．a feature story

C．a news report

D．a book review小题2: In the study, many dogs barked, jumped and scratched because __________.

A．they couldn’t find the bowl with food in it

B．they were left alone

C．they needed to be treated

D．they wanted to be active and optimistic小题3:According to Dr. Mendel, which statement is true?

A．Like humans, dogs are good at decision making.

B．Dog owners should train dogs to find food.

C．Emotional state works sometimes when humans make decision.

D．Dogs can always find the bowl with food quickly.小题4:What can we learn from the passage?

A．Dogs will be optimistic as long as they are left alone.

B．Dogs must be in a permanent bad mood when their owners left.

C．Dogs that express anxiety don’t need treatment.

D．Dogs may easily show their pessimistic outlook in learning ability.

跨膜蛋白属于（）

A.整合蛋白（integral protein）

B.外周蛋白（peripheral protein）

C.脂锚定蛋白（lipid-anchored protein）

D.整合蛋白或外周蛋白

太阳所含氢是够燃烧100亿年，到氢燃烧末期后，太阳就会消失。

下列句子，没有语病的一句是( )。

A．人文世界在人类总体世界建构中具有重要价值，人文知识与自然知识、社会知识相比较具有其独特性

B．从云龙山北望，不远处便有一个高耸的土山，那便是被项羽尊称为“亚父”的范增墓

C．当我同天真的孩子们一起重看这部影片，听着他们的欢声笑语时，也想起了自己的童年

D．在一些发展中国家，一辆旧西德“奔驰”牌轿车有时可换两辆新的日本轿车