Unit 4 Astronomy：the science of the stars 1．astronomy(n.) 天文学2．system(n.) 系统；体系；制度3．theory(n.) 学说；理论4．atmosphere(n.) 大气层；气氛5．fundamental( adj.) 基本的；基础的6．thus(adv.) 因此；于是7．puzzle(vt.& vi.) (使)迷惑；(使)为难 (n.) 谜；难题8．gentle(adj.) 温和的；文雅的9．crash(vi.& vt.) 碰撞；坠落10．pull(n.& vt.) 拉(力)；拖；牵引力11．float(vi.& vt.) (使)浮动；(使)漂浮(n.) 漂浮物12．violent(adj.)猛烈的；激烈的；强暴的→violence(n.)暴力→violently(adv.)暴力地；猛烈地13．unlike(prep.)不同；不像→like(vt.)喜欢；(prep.)相像的→likely(adj.)可能的14．harmful(adj.)有害的→harm(n.& v．)伤害→harmless (adj.)无害的15．exist(vi.)存在；生存→existence (n.)存在；生存1．prevent...from... 阻止……2．lay_eggs 下蛋3．in_one’s_turn 轮到某人；接着4．get_the_hang_of 熟悉；掌握；理解5．watch_out 密切注视；当心；提防6．depend_on 依靠7．in_time 及时，终于8．give_birth_to 产生；分娩9．cheer_up 感到高兴；感到振奋10．now_that 既然11．break_out 突发；爆发1．What is even more important is that as the earth cooled down，water began to appear on its surface.更为重要的是，当地球冷却下来时水开始在地球表面出现了。名师指津：what 引导主语从句。1例句仿写：她告诉我，那个时候她需要的就是一些好运气。What_was_needed at that time，she told me，was some good luck.2 ． The earth became so violent that it was not clear whether the shape would last or not.地球变得如此激烈动荡以至于不知道这个固体形状是否会继续存在下去。名师指津：whether...or not 是否……例句仿写：他们是否能够通过交流达成协议还不清楚。It’s not clear whether they are able to arrive at an agreement through communication or_not.3．But when I tried to step forward，I found I was carried twice as far as on the earth and fell over.而当我试着向前迈步的时候，我发觉我被送出去很远，步子的跨度竟是在地球上的两倍，因而我摔倒了。名师指津：“twice as＋形容词原级＋as”是倍数表达法之一。例句仿写：仔细研究地图后，我...
