简述熔融缩聚与溶液缩聚的局限性。

阅读短文，根据短文内容选择所给问题的答案。

Dear friends,

My name is Tony. I am English. I am twelve years old this year. I am tall, and I am good at playing football. I am in Grade Seven. There are thirty boys and twenty girls in my class. We are learning Chinese in our school. Our Chinese teacher is Mr. Wu. He is a little short, but he is very strong. He is very nice to us. I have some good friends in my class. Tom is a tall boy and has short black hair. He is good at playing football, too. Alice is short and she loves wearing red dresses. She is good at English. Shelly has long hair. She can speak Japanese and she likes swimming. We all study hard.

What about your school and your friend?  Please write soon.

Yours,

Tony

小题1:Which country is Tony from?

A．America.

B．England.

C．China.

D．Japan.小题2:Who is Mr. Wu?  

A．He is Tony’s English teacher.

B．He is Tony’s father.

C．He is Tony’s friend.

D．He is Tony’s Chinese teacher.小题3:How many students are there in Tony’s class?

A．50.

B．30.

C．20.

D．52.小题4:Who likes swimming?

A．Tom.

B．Alice

C．Shelly.

D．Mr. Wu.小题5:Who writes this letter?

A．Tony

B．Tom.

C．Shelly.

D．We don’t know.

商场里有两批商品，都卖1200元．其中一批赚了20%，另一批却亏了20%．经理最后计算这两批商品的利润时，发现是（　　）

A．不赚也不亏

B．赚了100元

C．亏了100元

D．无法判断

______,I realized what I'd said,but it was too late. [ ]

A. Constantly                  

B. Frequently

C.  Abruptly                  

D. Repeatedly

甲、乙两种物质的溶解度曲线如图。t₁℃时，在两支试管中分别加入等质量的两种物质，再分别加入等量的蒸馏水，充分振荡后，试管底部均有未溶解的固体。再将两支试管升温到t₂℃（不考虑溶剂质量变化）。由t₁℃到t₂℃的过程中，下列说法正确的是

A．甲溶液中溶质的质量分数减小

B．装有乙物质的试管中剩余的固体增多

C．甲、乙两种物质的溶解度都增大

D．两支试管里剩余的固体质量相同

国际上，工程咨询公司最基本、最广泛的业务是( )。

A．为业主服务

B．为承包商服务

C．为贷款方服务

D．联合承包工程