2. 职称英语
  3. The pearl is a lustrous rounded gem formed inside a mollusk (软体动物) . Since

The pearl is a lustrous rounded gem formed inside a mollusk (软体动物) . Since

游客2023-12-13  20
问题     The pearl is a lustrous rounded gem formed inside a mollusk (软体动
物) . Since pearls may be formed by any shelled mollusk, the most valu- (1) ______
able pearls are obtained from the oysters. Except for imitation pearls, which (2) ___
are entirely man-made, all pearls are formed from a secretion (分泌物)
around an irritating body that enters the soft tissue of a mollusk.
    If an irritating body enters the mollusk by accident, a natural pearl (3)______
forms. A cultured pearl forms if the irritating body is deliberately placed in
the mollusk by the man. (4)______
    Unlike to other gems, pearls have a natural luster, and they do not need (5)______
to be polished. Although they are usually white or cream-colored, they may
also be any shade of pink, yellow, green, grey, or black. The most desirable
pearls are white with a creamy or pinkish cast. Black pearls are also very
valuable because of their scarce. (6)______
    Imitation pearls are often made to appearing very similar to natural (7)______
pearls. Moreover, they do not have the luster of natural or cultured pearls. (8)______
Another way of distinguishing between imitation and natural or cultured
pearls is by gently rubbing the pearls through the surface of a tooth. Imita- (9)______
tion pearls feel smoothly, while natural or cultured pearls feel rough. (10)______ [br] (8)
选项
答案 Moreover — However
解析 moreover是一个连接性副词，关键看它是否正确地连接了前后两个句子。前一个句子的意思是人造珍珠看起来和天然珍珠非常相似。后一个句子的意思是它们没有天然珍珠或养殖珍珠的光泽。两个句子的关系显然不是递进，而是转折的关系，所以应该用上另一个连接性副词however。
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