黄体酮分子结构有（） A.α-醇酮基 B.A环上有△4-3-酮基 C.C-20上具有

在光学显微镜下可以观察到的结构是

A．人口腔上皮细胞的细胞壁

B．草履虫体内的叶绿体

C．烟草花叶病毒的蛋白质外壳

D．黄瓜表层果肉细胞的叶绿体

阅读理解。

     In the USA, there are many types of restaurants. Fast food restaurants are very famous. You can

find McDonald's and Kentucky Fried Chicken in many countries around the world. You look at a

menu above the counter(柜台), and say what you'd like to eat. You pay the person who serves you.

You take your food and sit down or take it away. There's no need to leave a tip"(小费)．

     In a coffee shop you sit at the counter or at a table. You don't wait for the waitress to show you

where to sit. She usually brings you coffee when you sit down, You tell her what you'd like to eat and

she brings it to you. You pay the cashier as you leave.

     In a family restaurant the atmosphere is casual, but the waitress shows you where to sit. Often the

waitress tells you her name, but you don't need to tell her yours. If you don't eat everything, your

waitress gives you a doggy bag to take your food home. You add an extra fifteen percent to the bill as

a tip．

     In top class restaurants, you need a reservation (预定) and you need to arrive on time. The waiter

shows you where to sit．If you have wine, he may ask you to taste it. You can only refuse it if it tastes

bad, or if you don't like it. When you get your bill, check it and then add fifteen to twenty percent to it

as a tip for the waiter．

1．There are _____ types of restaurants here．

A．three          

B．four            

C．five            

D．six   

2．You pay the person who _____ at the fast food restaurant．

A．brings food to you                    

B．tells you her name

C．shows you the seat                    

D．you talk to    

3．We should sit _____ in a coffee shop．

A．near the door                        

B．in the corner    

C．at the counter                        

D．on the floor

4．In what kind of restaurant does the waitress often tell you her name?     

A．In a top class restaurant：              

B．In a fast food restaurant．  

C．In a coffee shop．                    

D．In a family restaurant．

5．How much do you need to tip in a top class restaurant?    

A．Ten percent．                        

B．Fifteen percent．

C．Thirty percent．                    

D．Forty percent．

下列图像描述正确的是     

A．根据图①可判断可逆反应“A₂(g)+3B₂(g)2AB₃(g)”的ΔH＞0

B．图②表示压强对可逆反应2A(g)+2B(g)3C(g)+D(s)的影响，乙的压强大

C．图③可表示乙酸溶液中通入氨气至过量过程中溶液导电性的变化

D．根据图④，若除去CuSO₄溶液中的Fe³⁺可采用向溶液中加入适量CuO，至pH在4左右

装药和爆破前，出现哪些情况严禁装药爆破？

盆地的盖层