冷加工硬化和时效硬化

某同学学习了开花结果后，想观察一下玉米怎样结出果实、种子的。于是种了一些玉米，让他感到意外的是，用其他植物的花粉进行授粉的玉米，没有结出果实、种子。于是他产生了疑问：植物体要结出果实和种子，是不是一定要授同种植物的花粉呢？

（1）请问：假如他要用实验证明自己的疑问，应该做出的假设是                                                    。

（2）实验过程中，他重新种植了一些玉米（不考虑季节影响），并将这些玉米平均分成差不多的甲、乙两组。快开花时，将所有雄花去掉，并分别用半透明纸袋将玉米雌花花穗包起来，其意义是              。

（3）分别采集玉米和其他植物的花粉。将玉米花粉撒到包好的甲组玉米雌花穗上。其他植物的花粉撒到包好的乙组玉米雌花花穗上。根据假设可以预测，能够形成果实的一组是     。

（4）要设计另一组的意义是            .

（5）这种实验不能够只种两株玉米，也不能只进行一次实验，还不能局限一种植物进行实验，请说出其中的道理              。

肺真菌病影像学表现的病理基础有__________、___________、_____________、_______________、_______________和_____________。

在AutoCAD中，若想在输入文本时可灵活改变字符高度，在STYLE命令中，提示“HEIGHT”下输入（）。

A.任意大的正数后回车

B.一个负数后回车

C.0后回车

D.回车

《中 * * 办公厅国务院办公厅关于严禁党政机关及其工作人员在公务活动中接受和赠送礼金、有价证券的通知》规定，各地区、各部门、各单位（包括企业、事业单位）不得以业务会、招待会、订货展销会、新闻发布会等各种会议和礼仪、庆典、纪念、商务等各种活动及其他的形式或名义向党政机关及其工作人员赠送（）。

A.土特产

B.纪念品

C.礼金和有价证券

D.礼品

Now which are the animals really to be pitied in captivity First, those clever beings whose lively urge for activity can find no outlet behind the bars of the cage. This is most conspicuous, even for the uninitiated, in the case of animals which, when living in a free state, are accustomed to roaming about widely. Owing to this frustrated desire, foxes and wolves housed, in many old-fashioned zoos, in cages which are far too small, are among the most pitiable of all caged animals.
Though pinioned swans generally seem happy, under proper care, by hatching and rearing their young without any trouble, at migration time things become different: they repeatedly swim to the lee side of the pond, in order to have the whole extent of its surface at their disposal, trying to take off. Again and again the grand preparations end in a pathetic flutter of their half wings ; a truly sorry picture !
This, however, rarely awakens the pity of the zoo visitor, least of all when such an originally highly intelligent and mentally alert animal has deteriorated, in confinement, into a crazy idiot, a very caricature of its former self. Sentimental old ladies, the fanatical sponsors of the societies for Prevention of Cruelty to Animals, have no compunction in keeping a grey parrot in a relatively small cage or even chained to a perch. Together with the large corvines, the parrots are probably the only birds which suffer from that state of mind, common to prisoners, namely, boredom.

According to the author in Paragraph 1, what animals suffer most in captivity

A．Climbing animals.

B．Hunting animals.

C．Parroting animals.

D．Singing animals.