举例说明微生物之间的竞争关系。

“Everybody loves a bargain.” Is a well-known saying. One person’s useless, ugly, or broken object can be another person’s bargain. That is why so many Americans do not throw things away.  They put them outside their house.  They put on a "For Sale" sign.  And, as simple as that, they have a yard sale.

The sellers put a paid announcement in a local newspaper.  It tells when and where the yard sale will take place. These sales are very popular during weekends in spring, summer, and autumn.

Early in the morning, all the things to be sold are carried out of the house. Then they sit all day in the sunlight -- like tired guests at a party -- waiting for someone to take them home.

Just about anything can be sold at a yard sale. Sometimes, there are more clothes than anything else. Cooking equipment is also popular. So are old toys, tools, books, tables, and chairs. Then there are objects called "white elephants."  A white elephant is something you think is extremely ugly or useless. It may be an electric light shaped like a fish. You feel a sharp pain whenever you look at it. To someone else, however, it might be a thing of beauty and joy.

Some people go to yard sales to find a special thing that they collect. It may be old toy trains, for example, or paintings of dogs. Experts say more Americans are collecting old things now than ever before. Most people who go to yard sales, however, are not looking for anything special.  They might buy an object simply because it costs so little.  They enjoy negotiating over prices, even if they really do not need the object.  Later, they may hold their own yard sale to sell all the things they have bought.

小题1:What kind of things will go to a yard sale?

A．Cheap and ugly things．

B．Things people no longer use．

C．Things out of season．

D．Things of great value．小题2:A white elephant refers to ______ ．

A．something that can cause n feeling of pain

B．something disliked by the owners while appreciated by others

C．something sold at the lowest price

D．a toy shaped like a fish小题3:Most people go to yard sales to ______ ．

A．find Valuable paintings

B．look for something special

C．find a bargain

D．kill their time小题4:Which of the following is NOT true about a yard sale?

A．It may not be held when the weather is very cold．

B．It can last for a whole day．

C．It is usually held with a party．

D．It is held outdoors．小题5:We can infer from the last paragraph that ______ ．

A．people may find something of great value on a yard sale

B．yard sales only attract those who have a low income

C．things on a yard sale can cost people a lot

D．most people who go to yard sales want to make money

李明同学说话喜欢引经据典，在下面几种情境讲话时，他引用的古诗文恰当得体的一项是[ ]

A．同学张华要到外地去上中专，李明给他送行时说：“‘与君离别意，同是宦游人’。张华，你一人远走他乡要多多珍重啊！”

B．同学刘欣作文时想找一句表现读书乐趣的名句，李明不假思索地说道：“这还不容易，‘谈笑有鸿儒，往来无白丁’嘛！”

C．李明和同学一起去春游，面对着满园盛开的梨花，他情不自禁地说道：“真可谓‘忽如一夜春风来，千树万树梨花开’，太美了！”

D．李明的同桌张海学习上得过且过，不求甚解，李明意味深长地对他说：“‘学而不思则罔’，你可不能总是浅尝辄止啊！”

广告是一种主要地品牌传播手段，以（）为主体，（）为中心，对（）进行的以品牌名称、品牌标志、品牌定位、品牌个性等为主要内容的宣传活动。

A.创意

B.社会大众

C.策划

D.宣传

E.目标受众

提高分馏塔汽提蒸汽量有影响的是（）。

A.分馏塔顶油气分压升高

B.减少轻组分的顶拔出

C.可以提高柴油闪点

D.可以降低柴油溴价

价格评估鉴定的注意事项。