Q32:
Navigators have known for thousands of years that the ocean has variable currents, but it is only in the last half century that a reasonably clear picture has emerged of the patterns and causes of ocean currents.
A a reasonably clear picture has emerged of the patterns and causes of ocean currents
B a reasonably clear picture of the patterns of ocean currents and their causes have emerged
C a reasonably clear picture emerged of ocean currents, their patterns and the causes of them
D there have emerged a reasonably clear picture of the patterns of ocean currents and what caused them
E there had emerged a reasonably clear picture of the patterns of ocean currents and their causes
Answer: A
of the patterns and causes of ocean currents为什么放在emerge后面呀？
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