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【单选题】
某化合物的相对分子质量 Mr=72 ,红外光谱指出,该化合物含羰基,则该化合物可能的分子式为( )。A.
C 4 H 8 O
B.
C 3 H 6 NO
C.
C 3 H 4 O 2
D.
(A) 或 (B)
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【简答题】.完形填空。 Tom woke up on Monday morning. He felt 1 . He always felt sick on Monday mornings. He had to go to school for a 2 week! He almost wished there were no week-ends. 3 was even more difficult for ...
【简答题】视近物时,眼的调节包括 _______、 _______ 、 _______。
【单选题】看近物时的视觉调节过程包括
A.
、晶状体变凸，眼轴会聚，瞳孔散大
B.
、晶状体变凸，眼轴会聚，瞳孔缩小
C.
、晶状体扁平，眼轴会聚，瞳孔缩小
D.
、晶状体扁平，眼轴会聚，瞳孔散大
【简答题】“ It was a 1 surprise to me. I asked him 2 he helped me. He told me that he was also fond of 3 but was afraid of cycling at 4 . He wished that people would help him at those 5 , so he helped me,” said...
【单选题】正常人眼在视近物时的视觉调节过程包括
A.
晶状体变凸,瞳孔缩小,视轴会聚
B.
晶状体变凸,瞳孔不变,视轴会聚
C.
晶状体变凸,瞳孔缩小,视轴不变
D.
晶状体不变,瞳孔缩小,视轴会聚
【简答题】He realized that he was severely inadequate in communicating with people because he wasn't even able to say, express, and explain things properly.
【简答题】Choose the best answer for the following blanks taken crept trimmed for granted overhead rose beloved clutched As a young boy, the writer (1) ____________ his parents talking about h...
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