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【单选题】
对于尖顶直动从动件凸轮机构,在其余条件不变的情况下,基圆半径越小,则其压力角( )A.
越大
B.
越小
C.
不变
D.
两者无关
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【简答题】S upply the missing information according to the story. I t is a 1.______________________________ day. Bill Porter stopped at the first house. He 2. ____________ the bell. A woman comes to the door an...
【简答题】Suppose that the market can be described by the following three sources of systematic risk with associated risk premiums. The return on a particular stock is generated according to the following equat...
【多选题】关于遗传印记的描述正确的是
A.
亲代来源依赖性单等位基因表达的现象称为遗传印记，又称为基因组印记（genomic imprinting），亲本印记（parental imprinting）
B.
传给子代的亲本基因在子代中表达的状况取决于基因来自母本还是父本的现象。该现象在合子形成时已经决定，是涉及基因表达调控的遗传。
C.
不遵循孟德尔定律，是一种典型的非孟德尔遗传，正反交结果不同。
D.
遗传印记的机制是：基因组在传递遗传信息的过程中，通过基因组的化学修饰（DNA的甲基化；组蛋白的甲基化、乙酰化、磷酸化、泛素化等）而使基因或DNA片段被标识的过程。
E.
遗传印记不属于表观遗传学范畴。
【简答题】Fill in the blanks according to the text . Fill in only one word with its appropriate form in each blank. Spend or save –the student’s dilemma I think that the messages we get from our environment se...
【单选题】(2009全国联赛,12)关于母性遗传,下面表述哪项是正确的?
A.
是母亲将遗传物质传递给子女而父亲不向子女传递遗传物质的现象
B.
是细胞质遗传的同义语，又称核外遗传
C.
是母亲的基因产物在卵细胞质之中积累而影响下一代表型的现象
D.
是细胞质基因仅由母亲传递给后代的遗传方式
【单选题】Text B I. Choose the best answer to each of the following questions according to what is stated or implied in the text.Which of the following statements is implied in the passage?
A.
When Tim Cook became angry with investors who questioned the notion of man-made climate change, he really meant putting CSR before profits.
B.
Bill Gates’ greatest contribution to the world lies in his insurmountable philanthropy.
C.
The good Apple can do is in inverse proportion to the profit it can make.
D.
The author is of the opinion that both extremes of the CSR debate are in the wrong direction.
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