煤层是由()转变而来的。A、岩石 B、植物 C、泥土

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问题:

煤层是由()转变而来的。

A、岩石

B、植物

C、泥土

考点:执业西药师煤矿防突工煤矿防突工题库
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若i是虚数单位,则i+2i2+3i3+…+2013i2013=______.

题型:单项选择题

阅读下面短文,从短文后各题所给的四个选项(A、B、C和D)中,选出可以填入空白处的最佳选项,并在答题卡上将该项涂黑。学科&网

Hundreds of people have formed impressions of you through that little device(装置) on your desk. And they’ve never actually   41   you. Everything they know about you   42   through this device, sometimes from hundreds of miles away.   43   they feel they can know you   44   from the sound of your voice. That’s how powerful the   45   is.

Powerful, yes, but not always   46  . For years I dealt with my travel agent only by phone. Rani, my faceless agent whom I’d never met   47  , got me rock-bottom prices on airfares, cars, and hotels. But her cold voice really   48   me. I sometimes wished to   49   another agent.

One morning, I had to   50   an immediate flight home for a family emergency. I ran into Rani’s office   51  . The woman sitting at the desk,   52   my madness, sympathetically jumped up. She gave me a   53   smile, nodded while listening patiently, and then printed out the   54   immediately. “What a wonderful lady!” I thought.

Rushing out   55   I called out over my shoulder, “By the way, what’s your name?” “I’m Rani,” she said. I turned around and saw a   56   woman with a big smile on her face waving to wish me a safe trip. I was   57  ! Why had I thought she was cold? Rani was, well, so   58  .

Sitting back in the car on the way to the airport, I figured it all out. Rani’s   59  ---her warm smile, her nods, her ‘I’m here for you’   60  ---were all silent signals that didn’t travel through wires.

53()

A.shy

B.comforting

C.familiar

D.forced

题型:单项选择题

剪切机根据其结构及工艺特点可分为四种类型:()、斜刃剪、圆盘剪和。

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按Angle错分类法,"磨牙为近中关系,下颌及下牙弓处于近中位置"属于()。

A.安氏Ⅰ类

B.安氏Ⅱ类一分类

C.安氏Ⅱ类二分类

D.安氏Ⅲ类

题型:单项选择题

下列是某化合物的结构简图,据图回答:

此化合物的名称是()

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