【点拨】lay v.下蛋，放置
lay the book on the table把书放在桌上
The hens are not laying well．现在那些母鸡不爱下蛋。
【拓展】
lay的相关短语：
lay off(暂时)解雇
lay out展开；布局，安排
lay down放下
lay aside把……放一边
【点拨】presence n．存在；出席，在场
常用结构
in the presence of sb.
＝in sb’spresence当着某人的面；有某人在场
presence of mind危难中镇定自若；遇事不慌
lose one’s presence of mind心慌意乱
Your presence is requested．敬请光临。
那得看情况而定。
(2) depend on=count on=rely on sb.
信任/相信/依赖/依靠
believe sb.相信某人(所说的话)
believe in sb.相信/信任/信赖某人
trust (in) sb.相信/信任/信赖某人
encourage
【原句回放】They multiplied and filled the oceans and seas with oxygen，which encouraged the later development of early shellfish and allsorts of fish．(P26)它们繁殖起来就使得海洋充满了氧气，这为早期的贝类及其他各种鱼类的发育进一步创造了条件。
重点句型：
“be to+动词原形”的用法
it作形式宾语
whether的用法
知识讲解
重点词汇
【高清课堂：403623Astronomy 探秘天文学精讲词汇】
explode
重点例句：
It exploded loudly with fire and rock.
explode (v.)爆炸，爆发
(1) explode with anger
目标认知
重点词汇：
explode，escape，depend，encourage，violent，presence，allow，lay，exist，remain，prevent，force，pull，cheer，exhaust，warn，possible
重点短语：
in one’s turn，in time，a bit of
乘客不得吸烟。
We don’t allow smoking in our house．
我们不允许有人在我们家里吸烟。
Their teacher allowed them three days for the assignment．
他们的老师给他们三天时间完成作业。
lay
【原句回放】They produced young generally by laying eggs．(P26)它们一般是通过孵蛋而繁衍后代的。
【点拨】allow v.允许，许可
doing sth.允许做某事
allow + sb. to do sth.允许某人做某事
allow sb. sth.允许某人某事
My boss doesn’t allow me to use the telephone．
我的老板不允许我使用电话。
Passengers are not allowed to smoke．
escape
重点例句：
They are putting too much carbon dioxide into the atmosphere, which prevent heat from escaping from the earth into space.
escape
(v.)逃跑，逃避(n.)逃脱
be absent from school / work / a meeting不上学/上班/到会
allow
【原句回放】What many scientists believe is that the continued presenceof water allowed the earth to dissolve harmful gases and acids intothe oceans and seas．(P26)很多科学家相信，由于地球上长期有水存在，它使得地球把有害气体和酸性物质溶解在海洋里。
温馨提示
remain不能用于被动结构。
prevent
【原句回放】...which prevents heat from escaping from the earth into space．(P26)……这使得地球上的热不能释放到太空中去。
【点拨】(1)prevent v.阻止，预防
Vitamin C is supposed to prevent colds．
勃然大怒
explode into laughter
放声大笑
the exploding world population
迅速增长的世界人口
(2) explosion
(n.)爆炸
explosive
(adj.)易爆的
(n.)爆炸物；炸药；迸发(感情)；
(人口等)突增
完成句子
(1)Two bombs ________ (爆炸) in front of the park gate，causing two deaths.
我去了城市，可弟弟留在了家里。
In spite of their quarrel，they remained the best of friends．
他们尽管吵过架，却仍不失为最好的朋友．
【拓展】
remains n.剩余物，废墟
remaining adj.剩余的(作前置定语)
the remaining money剩下的钱
【点拨】encourage vt.
鼓励，鼓舞encourage sb.to do sth．鼓励某人做某事
激励，促进High prices encouraged farming．高价格刺激了农业。
【拓展】
encouraging adj.令人鼓舞的
encouragement n.鼓舞，鼓励
courage n.勇气
作为动词，常用于下列结构或短语中：
escape from...从……逃走
escape sth.逃避某事
escape doing sth.(不能接to do形式)逃避做某事
sth. escape sb./sb.’s attention/sb.’s notice
某物没引起某人的注意；某人没记住某物
翻译句子
escape from prison越狱
escape being punished＝escape punishment
逃脱被惩罚，免受惩罚
【原句回放】Why they suddenly disappeared still remains a mystery．(P26)它们为什么会突然灭绝至今仍是个谜。
【点拨】remain link v.保持不变，仍是
常用结构
remain modest and prudent保持谦虚谨慎
I went to the city，but my brother remained at home．
keep sb./sth.from doing sth.
Who prevents their plans(from)being carried out?
谁阻止他们的计划被实施?
(2)escape v.& n.逃脱，避开，溜走；安全出口
escape from...逃离……
escape doing...逃避……
(2)Suddenly Charles _______________________ (勃然大怒)．
(3)There will be no standing room on the earth ________________________________________
(由于激增的世界人口)．
discourage vt.使泄气
discouraging adj.令人泄气的，令人沮丧的
discourage sb.from doing阻止某人做……
violent
【原句回放】The earth became so violent that it was not clear whether the shape would last or not．(P25)地球(开始)变得激烈动荡，不知道这个固体形状是否会继续存在下去。
lay sth.up储备某物
lay sth.on供应某物
易混辨析
注意下列动词的过去式、过去分词及现在分词形式：
动词原形
词义
过去式
过去分词
现在分词
lying
lie
躺，位于
lay
lain
lying
lay
放置，产卵
laid
laid
laying
exist
【原句回放】They laid eggs too and existed on the earth for more than 140 million years．(P26)它们也生蛋，在地球上生存了1.4亿多年。
depend
重点例句：
Whether life will continue on the earth for millions of years to come will depend on whether this problem can be solved.
(v.)依靠，依赖