【多选题】吴健雄所做的极化Co-60实验,以下说法正确的是
A.
自然条件下无法观察到Co-60 β衰变过程中的宇称不守恒现象
B.
吴健雄采用了低温和磁场环境,使Co-60的自旋方向更加容易分辨
C.
极化Co-60实验验证β衰变过程中的宇称不守恒原理是观察β粒子在自旋向上和自旋向下两个方向上的电子计数
D.
李政道和杨振宁因为建议吴健雄做极化Co-60实验而获得了诺贝尔物理学奖
E.
低温情况下,非极化核Co-60自旋取向比较一致
【单选题】鲜叶保鲜必须控制两个条件,一个是( )和适当降低鲜叶含水量。
【单选题】( )是保险合同所保障的对象,享有保险金请求权的人。
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【简答题】阅读理解 A handsome middleaged man walked quietly into the caf? and sat down.Before he ordered,he couldn't help but noticed a group of younger men at the table next to him.It was obvious they were ...