问题
单项选择题
龋病的主要病原因素为（）。
A.食物
B.易感牙面
C.细菌
D.一定的时间
E.以上因素均是
答案
参考答案：C
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龋病的主要病原因素为（）。
A.食物
B.易感牙面
C.细菌
D.一定的时间
E.以上因素均是
参考答案：C
| 完形填空。 | |||
| In the doorway of my home，I looked closely at my 23yearold son，Daniel.In a few hours he would be flying to France to __1__ a different life.It was a transitional(过渡的) time in Daniel's life.I wanted to __2__ him some words of significance.But nothing came from my lips，and this was not the __3__ time I had let such moments pass. When Daniel was five，I took him to the bus stop on his first day of kindergarten.He asked，“What is it going to be like，Dad? Can I do it？” Then he walked__4__ the steps of the bus and disappeared inside.The bus drove away and I said nothing.A decade later，a similar __5__ played itself out.I drove him to college.As I started to leave，I tried to think of something to say to give him __6__ and confidence as he started this new stage of life.Again，words __7__ me. Now，as I stood before him，I thought of those__8__ opportunities.How many times have I let such moments __9__ ? I don't find a quiet moment to tell him what they have __10__ to me.Or what he might want to face in the years __11__.Maybe I thought it was not necessary to say anything.What does it matter in the course of a lifetime if a father never tells a son what he really thinks of him？__12__ as I stood before Daniel， I knew that it did matter.My father and I loved each other.Yet，I always__13__ never hearing him put his__14__into words.Now I could feel my palms sweat and my throat tighten.Why is it so __15__ to tell a son something from the heart? My mouth turned dry，and I knew I would be able to get out only a few words clearly.“Daniel，” I said，“If I could have picked，I would have picked you.” That's all I could say.He hugged me.For a moment，the world__16__ and there were just Daniel and me.He was saying something，but tears misted my eyes，and I couldn't understand what he was saying.All I was__17__ of was the stubble(短须) on his chin as his face pressed__18__ mine.What I had said to Daniel was __19__.It was nothing.And yet， it was __20__ . | |||
| ( )1．A.experience ( )2．A.show ( )3．A.last ( )4．A.upward ( )5．A.sign ( )6．A.interest ( )7．A.failed ( )8．A.future ( )9．A.last ( )10．A.counted ( )11．A.forward ( )12．A.But ( )13．A.wondered ( )14．A.views ( )15．A.important ( )16．A.disappeared ( )17．A.sensitive ( )18．A.by ( )19．A.clumsy ( )20．A.none | B．spend B．give B．first B．into B．scene B．instruction B．discouraged B．embarrassing B．fly B．meant B．before B．And B．regretted B．actions B．essential B．changed B．convinced B．against B．gentle B．all | C．enjoy C．leave C．very C．down C．scenery C．courage C．struck C．obvious C．pass C．valued C．ago C．Instead C．minded C．feelings C．complex C．progressed C．aware C．on C．absurd C．anything | D．shape D．instruct D．next D．up D．sight D．direction D．troubled D．lost D．remain D．eared D．ahead D．So D．tried D．attitudes D．hard D．advanced D．tired D．with D．moving D．everything |