请教36套阅读EX16

lionelfengUID: 2371460

When a molten metal or metallic alloy is cooled to a solid, a crystalline structure is formed that depends on the particular alloy composition. In contrast, molten nonmetallic glass-forming materials, when cooled, do not assume a crystalline structure, but instead retain a structure somewhat like that of the liquid--an amorphous structure. At room temperature, the natural long-term tendency for both types of materials is to assume the crystalline structure. The difference between the two is in the kinetics or rate of formation of the crystalline structure, which is controlled by factors such as the nature of the chemical bonding and the ease with which atoms move relative to each other. Thus, in metals, the kinetics favors rapid formation of a crystal line structure, whereasin nonmetallic glasses the rate of formation is so slow that almost any cooling rate is sufficient to result in an amorphous structure.

12. It can be inferred from the passage that, theoretically, molten nonmetallic glasses assume a crystalline structure rather than an amorphous structure only if they are cooled
(A) very evenly, regardless of the rate
(B) rapidly, followed by gentle heating
(C) extremely slowly
(D) to room temperature
(E) to extremely low temperatures

yeanshinUID: 3125778

这题当时做我也想了很久。。
At room temperature, the natural long-term tendency for both types of materials is to assume the crystalline structure. 也就是说理论上室温下长期就可以，后文解释的是为什么实际中没有这样。
whereasin nonmetallic glasses the rate of formation is so slow that almost any cooling rate is sufficient to result in an amorphous structure. 比较了金属和玻璃之后的结论是金属结晶快，而玻璃慢，因此就需要更慢的冷却速度。通常情况下都会变成无定形结构。。

个人见解。。

lionelfengUID: 2371460

2# yeanshin
你说的有道理，但是在第二点上面有点跳跃，我不知道我这样的理解是不是和你说的是一样的
首先，我也是定位在了最后一句话
whereas in nonmetallic glasses the rate of formation is so slow that almost any cooling rate is sufficient to result in an amorphous structure
sufficient在韦氏字典的解释： enough to meet the needs of a situation；我个人觉得sufficient在这里多、快、充足这样的感觉。
这句话的意思也就是：formation太慢了以至于 无论冷却的多慢 对于  result in an amorphous structure 都是足够快了。
如果没有formation太慢这个前提的话，正常情况应该是冷却速度越快，越有可能导致result in an amorphous structure。
可以做个类比：
因为：姚明太高了以至于 无论他跳的多低 对于他能摸到篮筐都是足够高了
所以：对于正常人来讲，跳的越高，就越有可能摸到篮筐

lionelfengUID: 2371460

补充：在老题原文后面有这样一句话
“ For glassy metals to be
(35) formed, the molten metal must be
　　cooled extremely rapidly so that
　　crystallization is suppressed.
　　The structure of glassy metals
　　is thought to be similar to that
(40) of liquid metals.”
:)