影响饱和砂土及粉土液化的因素很多，除规范中列出的地质年代，土中黏粒含量，上覆非液化土层厚度和地下水位深度外，下述说法中正确的是（）。
A.砂土的密实程度是影响土层液化的重要因素，如Dr<50%的砂土普遍发生液化，而
B.土层的埋深越大，侧压力越大，土层越易发生液化
C.地震烈度越高，地面运动强度就越大，土层越容易发生液化，一般在6度烈度及其以下地区可不考虑液化问题
D.震动作用的持续时间越长，越容易液化，因此某场地在遭受到相同烈度的远震比近震更容易液化，因为前者对应的大震持续时间比后者对应的中等地震持续时间要长
参考答案：A, C, D
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| Yesterday, our teacher asked us when people could be considered old. David said that when people got wrinkles (皱纹). However, Mary didn't__1__. She thought people might gain wrinkles at an earlier age because of their__2__work. Then Lily said that those__3__ their 60s or more could be called old people. This time, Emily expressed her doubt. She said that some old people might__4__be full of energy and working on their dreams, which made them appear__5__ .The class was over and the teacher asked me to continue to__6__it after class. The question__7__me of a saying of J.Barrymore: a man isn't old__8__ he is pursuing (追求 ) something. My grandma is such a woman who__9__her dream even when she's 70 now. She has kept her dream of being a painter since she was a little child__10__, because her family was poor, she had to__11__ her dream. She had to work to raise money so as to__12__ her family. Although she had never forgotten her dream, she could hardly find any__13__to make it come true because of the tough work. Fortunately, a(n)__14__ came when she retired from her work. She__15__taking painting lessons even though she was already old. At first, I was __16__ her idea of attending school at such an old age, but after seeing her paint happily and enjoyably, I began feeling it a good__17__.She looks fine and seems__18__. So if we have our dreams and try to__19__ them, we aren't old. If we don't know what we want and let regrets be the__20__point of our lives, then we can be considered old. | |||
| ( )1.A.answer ( )2.A.exciting ( )3.A.reaching ( )4.A.sometimes ( )5.A.attractive ( )6.A.think about ( )7.A.prevented ( )8.A.even if ( )9.A.remembers ( )10.A.However ( )11.A.give up ( )12.A.combine ( )13.A.way ( )14.A.success ( )15.A.stopped ( )16.A.on ( )17.A.choice ( )18.A.gentle ( )19.A.satisfy ( )20.A.tip | B.agree B.common B.avoiding B.almost B.young B.look for B.spotted B .as if B.follows B.Also B.search for B.protect B.person B.chance B.considered B.for B.dream B.energetic B.express B.bottom | C.move C.hard C.repeating C.hardly C.smart Crefer to C.reminded C.so that C.knows C.Fortunately C.put aside C.leave C.place C.excuse C.liked C.against C.tas k C.wealthy C.change C.center | D.understand D.old D.confirming D.still D.interesting D.turn to D.puzzled D.as long as D.finds D.Approximately D.return to D.support D.service D.helper D.began D.with D.purpose D.penniless D.realize D.side |