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【单选题】
It can be inferred from the passage that scientists are 'perplexed by the means' (line 12) for which of the following reasons?A.
They are unsure of how alanine remains separate from the everyday nitrogen metabolism of the plant itself.
B.
They have yet to establish what function the alanine serves for the soybean plants.
C.
They have thought alanine to exist only in very small quanties in rhizobia.
D.
They have long considered the membranes of the soybean plant impermeable to amino acids.
E.
They are uncertain how such a rapid export of fixed nitrogen is possible through the soybean membranes.
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【多选题】与普通法律相比，宪法的主要特征有( )。
A.
宪法往往由特别成立的机关制定和修改
B.
宪法具有特别的制定和修改程序
C.
宪法具有最高的法律地位或法律效力
D.
宪法规定的是公民的基本权利和基本义务
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A.
成虫掠夺营养
B.
幼虫移行对肺部的损伤
C.
成虫寄生引起的并发症
D.
成虫体代谢物和崩解产物引起的超敏反应
E.
成虫破坏肠粘膜影响吸收
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A.
． 液化性坏死
B.
固缩坏死
C.
． 干性坏疽
D.
湿性坏疽
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