轧辊按制造材料分可分为（）、（）、（）。

临床常见的气逆证，多与下列哪组脏腑关系密切

A．肺、心、肝

B．肺、脾、肾

C．肺、心、肾

D．肺、胃、肝

E．肺、胃、肾

分泌期晚期为月经周期的()

A．第1～4日

B．第11～14日

C．第15～19日

D．第20～23日

E．第24～28日

在“验证力的平行四边形定则”的实验中：  

(1)下列哪些方法可以减小实验误差___________。    

A．两个分力F₁、F₂间的夹角要尽量大一些    

B．两个分力F₁、F₂的大小要尽量大一些    

C．拉橡皮条的细绳要稍长一些    

D．实验中，弹簧秤必须与木板平行，读数时视线要正对弹簧秤刻度

(2)如果共点力F₁、F₂的大小均不变，分力F₁固定，分力F₂顺时针转动180°的过程中，F₁和F₂的合力大小随着它们的夹角θ变化的关系如 图所示。如果F₂继续转动180°，回到原来位置，试在图中画出F₁和F₂的合力大小随着它们的夹角θ变化的关系，并计算出F₁、F₂两分力大小分别为___________、___________。

Jurassic Park could become a reality with dinosaurs making a comeback after a discovery last week. Scientists found remains of a dinosaur’s blood vessels（血管）and cells .In theory, DNA from these cells could be used to clone the longdead dinosaur.

A team from North Carolina State University found the remains in a fossil(化石)of the leg bone of a Tyrannosaurus rex（暴龙）in Montana, US.

The last dinosaurs on Earth died some 65 million years ago, but they left bits of themselves behind wherever they lived. Around the world ,dug-up bones and fossils have given scientists many ideas about what the animals were like.

Preserved by minerals, the newly discovered leg bone was hard. So the scientists used a liquid to dissolve（溶解）the minerals. A week later, the remaining material was soft and stretchy（有弹性的）,which surprised the researchers.

Some of the materials appeared to be a network of blood vessels. Out of these, the researchers were able to squeeze(挤出)tiny , round, dark-red and deep-brown structures that seemed to be ancient blood cells.

Scientists are overjoyed by this discovery because most fossils come from hard body parts, like bones and shells, which last a long time. Soft tissues, like skin, muscle, and organs are very hard to find because they tend to break down more quickly.

Scientists think that the new discovery will help them to better understand how fossils form. Future finds should also help flesh out how the dinosaurs lived.

They were also very excited by the possibility of having some dinosaur DNA.From that scientists could create a real life “Jurassic Park”.

In the Hollywood movie, scientists reproduced dinosaurs from the DNA they found in a mosquito fossil and disaster soon followed.

小题1:Scientists are excited _________________________ .

A．because they have got dinosaur DNA

B．about making a movie called “Jurassic Park”

C．because they found the liquid to dissolve fossils

D．because it,s very hard to find soft tissues in fossils小题2: The latest discovery can tell us       .

A．what the animals were like

B．how fossils form

C．how the dinosaur lived

D．how to get dinosaur DNA小题3:What does the underlined phrase“flesh out”mean in the article?

A．add more details or information to

B．take more photos of

C．make the public know more about

D．find the answer to小题4:Why is the latest discovery very important?

A．It could make it possible to make dinosaurs return to the former position.

B．It could throw light on how dinosaurs lived many years ago.

C．It could prove what dinosaurs were like.

D．It could explain why dinosaurs died some 65 million years ago.

地形图在工程上有哪些用途？