题干

下列说法正确的是(   )

A:太阳辐射的能量主要来自太阳内部的核裂变反应

B:原子核 90232Th 经过6次 α 衰变和4次 β 衰变后成为原子核 82208Pb

C:用升温、加压或发生化学反应的方法不能改变放射性元素的半衰期

D:以mD、mp、mn分别表示氘核、质子、中子的质量,则mD=mp+mn

E:天然发射现象中的γ射线是原子核受激发产生的

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B,C,E

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    It's generally believed that people act the way they do because of their personalities and attitudes. They recycle their garbage because they care about the environment. They pay $5 for a caramel brulee latte because they like expensive coffee drinks.

    It's undeniable that behavior comes from our inner dispositions(性情),but in many instances we also draw inferences about who we are,as suggested by the social psychologist Daryl Bern,by observing our own behavior.We can be strangers to ourselves.If we knew our own minds,why would we need to guess what our preferences are from our behavior?If our minds were an open book,we would know exactly how much we care about the environment or like lattes.Actually,we often need to look to our behavior to figure out who we are.

    Moreover,we don't just use our behavior to learn about our particular types of character—we infer characters that weren't there before.Our behavior is often shaped by little pressures around us,which we fail to recognize.Maybe we recycle because our wives and neighbors would disapprove if we didn't.Maybe we buy lattes in order to impress the people around us.We should not mistakenly believe that we always behave as a result of some inner disposition.

    Whatever pressures there can be or inferences one can make,people become what they do,though it may not be in compliance(符合)with their true desires.Therefore,we should all bear in mind Kurt Vonnegut's advice:"We are what we pretend to be,so we must be careful about what we pretend to be."