要观察、描述沉积岩碎屑的粒度大小，并按岩石粒度分级标准和岩石

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问题单项选择题

要观察、描述沉积岩碎屑的粒度大小，并按岩石粒度分级标准和岩石粒度命名原则进行岩石命名，碎屑粒度含量达（）以上者构成基本名称

A、40％

B、50％

C、60％

D、70％

答案

参考答案：B

选择题

The Charles Dickens Museum in Doughty Street is the only one of his London homes to survive，

______he wrote Oliver Twist.

A．where

B．that

C．which

D．what

单项选择题

Textile business has become more and more difficult( )the competition grew.

A．as

B．befor

C．since

D．after