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问题 选择题

霉菌与细菌在结构上有不同点是（　　）

A．霉菌有细胞质

B．霉菌有细胞壁

C．霉菌有叶绿体

D．霉菌有成形的细胞核

答案

细菌的结构包括细胞壁、细胞膜、细胞质、未成型的细胞核；真菌的结构包括细胞壁、细胞膜、细胞质和细胞核．所以真菌和细菌在结构上最大的区别就是真菌有成形的细胞核，细菌无成形的细胞核．霉菌属于真菌．因此霉菌与细菌在结构上主要的区别是霉菌有成形的细胞核．

故选D

单项选择题

Passage oneLong bus rides are like television shows .They have a beginning ,a Middle and an end –with commercials thrown in every three or four minutes .The commercials are unavoidable .They happen whether you want them or not .Every couple of minutes a billboard glides by outside the bus window . “buy super clean toothpaste”. “Drink Good’n Wet Root Beer .””Fill up with Pacific Gas .”Only if you sleep ,which site equal to turning the television set off ,are you spared the unending cry of “You Need It ! Buy It Now !” The beginning of the ride is comfortable and somewhat exciting ,Even if you’ve traveled that way before .usually some things have changed-new houses ,new buildings ,sometimes even a new road .The bus driver has a style of driving and it’s fun to try to figure it out the first hour or so . If the driver is particularly reckless or daring ,the ride can be an thrilling as a suspense story .Will the driver pass the truck in time Will the driver move into the right or the left –hand lane After a while,of course,the excitement dies down .sleeping for a while helps pass the middle hours of the ride .Food always makes bus rides more interesting .But you’ve got to be careful of what kind of foodyou eat .Too much salty food can make you very thirsty between stops. The end of the ride is somewhat like the beginning .You know it will soon be over and there’s a kind of expectation and excitement in that .The seat ,of course ,has become harder as the hours have passed.By now you’ve sat with you legs crossed ,with your hands crossed behind your head .the end comes just at the right time . There are just no more ways to sit.

The write of this passage would probably favor ( )

A． bus drivers who weren’t reckless

B．driving alone

C．a television set on the bus

D． no billboards along the road

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判断题

增大轧辊直径可降低轧制压力。
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