• ★continuously adv. 不断地，连续地（指动作中间没 有间断）
• You mustn’t watch TV for such a long time continuously.
• This plane can fly continuously for twenty hours. • continually adv. 频繁地，反复地（指动作中间有间
• 后面的从句用一般过去时 • had no sooner done…than +一般过去时, 固定
用法 (时态结构: 完成时态+ than + 一般过去 时)
• He had no sooner arrived than he called me up.
• no sooner 放在句首就要倒装
• No sooner had he arrived than he called me up. (倒装)
If you have ever been to England ,you must be impressed by the beautiful scenery.However,everyhing there is perfect except the weather.
• ★complain v. 抱怨 • complain to sb. 向某人抱怨 • complain of/about sth. 抱怨某事
• immediately
• 1.adv • He lay down and was asleep immediately. • All those who are immediately involved
will be informed of the decision.
• 2.conj. • I will tell him the news immediately he
• I can't afford it. ＝ It is more than I can afford.
• hardly…when… 还没来得及……就……，用 法同no sooner…than
• hardly had sb. done when… (hardly在 句首, 要倒装)
• He had hardly opened his eyes when he was knocked out.（knock out : 打晕 , 击倒）
• 那么，在一次抽样中，参数的估计值与真值 的差异有多大，是否显著，这就需要进一步进 行统计检验。
• 主要包括拟合优度检验、变量的显著性检验 及参数的区间估计。
一、拟合优度检验
拟合优度检验：对样本回归直线与样本 观测值之间拟合程度的检验。
度量拟合优度的指标：判定系数（可决 系数）R2
问题：采用普通最小二乘估计方法，已 经保证了模型最好地拟合了样本观测值， 为什么还要检验拟合程度？
1、总离差平方和的分解
已知由一组样本观测值（Xi,Yi），i=1,2…,n 得到如下样本回归直线
Yˆi ˆ0ˆ1Xi
y i Y i Y ( Y i Y ˆ i) ( Y ˆ i Y ) e i y ˆ i
新概念英语第二册-38课
1.What is your favourite
warming up city?
2.How is the weather there? 3.Have you ever been to England? 4.Do you know the climate in England?
断但又持续很久） • It rained continually. 天频繁地下雨。 • The river flows under this bridge continuously. 河
水不停地从桥下流过.
• ★bitterly adv. 刺骨地 • bitterly disappointed 彻底的失望（
gets back. • （directly，instantly）
§2.3 一元线性回归模型的统 计检验
一、拟合优度检验 二、变量的显著性检验 三、参数的置信区间
• 回归分析是要通过样本所估计的参数来代替总 体的真实参数，或者说是用样本回归线代替总 体回归线。
• 尽管从统计性质上已知，如果有足够多的重 复 抽样，参数的估计值的期望（均值）就等 于其总体的参数真值，但在一次抽样中，估计 值不一定就等于该真值。
连词as if/though引导方式状语从句，通常跟在描述 行为举止的动词之后，如act，appear，feel，look， smell，sound等后面： She acted as if she were mad. （虚拟语气） It feels as if/though it’sad he got into the bus when it began moving.
•as if( sometimes subjunctive mood )
•He acts as if he knew me.(事实上并不知道我) •They treat me as if I were a stranger. （我并不 是陌生人） •It looks as if it is going to rain (天要下雨)
disappoint vt.使失望）
• I am bitterly disappointed. • bitterly cold 刺骨地寒冷 • It’s bitterly cold. （chilly adj. 寒冷的）
• no sooner…than… 一……就……（关联词，引导 时间状语从句，主句里常用过去完成时，than
• No sooner had he begun speaking than he was interrupted.
• more than 表示“超过……的范围”
• This piece of news is more than I can believe.
• It was more than I could understand.