三角形具有______性．

Once there was a parrot on sale in a pet store. It was a beautiful red and blue bird. It sat on a perch in the middle of the store, so that everyone could see it when they came in. The owner was very proud of it and asked a high price for it.

One day a man went into the store. "That's a beautiful bird,"he said to the pet store owner, "But why is it so expensive? Is it unsual bird?"

"No, it's not very unusual. It's expensive because it can talk," the pet store owner said.

"I see. How can I make it talk?" the man asked.

The pet store owner asked him, "Do you see those string tied to each of the bird's legs?"

"Yes," the man answered.

"Well, you pull those strings," the pet store owner told him."That will make the parrot talk."

The man asked,"Do you mind if I try?"

"Not at all," the pet store owner said.

The man walked up to the parrot and pulled the string on its left leg. The parrot said, "Good morning."

The man pulled the string on the parrot's right leg. This time the parrot said, "How are you today?"

"That's not very interesting, " said the man. "Any parrot could do that." Then he laughed, "But what wold happen if I pulled both strings at the same time?"

"I'll fall off my perch, you fool!" the parrot said.

小题1:The parrot was expensive because________.

A．it was pretty beautiful

B．it could talk with the people

C．it was a very unusual bird

D．it was in the middle of the store小题2:The parrot would talk when _________.

A．people came into the pet store

B．it was the pet store owner

C．people said it was beautiful

D．people pulled the strings on its legs小题3:Which is the first sentences that the parrot said to the man?

A．Good morning.

B．How are you?

C．That's wasn't interesting.

D．I'll fall off my perch, you fool.小题4:From the story we know the parrot was_______.

A．kind

B．silly

C．clever

D．crazy小题5:The best title for the passage should be _________.

A．Unusual Parrot

B．Parrot Talk

C．Silly man

D．Clever Owner

属于癌症病人第二阶梯止痛的药是

A．SDA．
B．B
P．
C．J
P．
D．US
P．
E．WH
O．

中药配伍的目的是（）

A.增强疗效

B.减轻毒性

C.扩大治疗范围

D.适应复杂病情

E.改变药物的味

影响红细胞生成的最直接因素是( )。

A．铁的供给

B．雄激素

C．促红细胞生成素

D．组织内O₂分压降低

E．叶酸

个人取得的下列所得中，不免征个人所得税的是（）。

A、救济金

B、专利被侵权所获赔款

C、退休工资

D、政府特殊津贴