九年
2=0， 所以 a+b=2． 故选 B． 【点评】本题考查了一元二次方程的解：能使一元二次方程左右两边相等的未知数 的值是一元二次方程的解． 9．如图，在 △ ABC 中， AD， BE 是两条中线，则 S△ EDC： S△ ABC=（ ） A． 1： 2 B． 1： 4 C． 1： 3 D． 2： 3 【考点】 S9：相似三角形的判定与性质． 菁优网版权所有 【分析】由在 △ ABC 中，
后，闭合开关，发现灯泡发光，电压表的指针有明显偏转，但电流表的指针却没有偏转，请问发生这种现象的原因是： ________________. （ 3）排除故障后，它们根据测量出的实验数据画出了如图乙所示的 I﹣ U 图象，由此可知小灯泡的额定功率为 ________W. 7． “测定小灯泡的电功率 ”的实验原理是 ______连接电路时电键应处于 ______状态，在 “探究平面镜成像的特点
•doubt 在肯定句中一般接“ if/whether”引导的从句； •doubt在否定句中一般接” that”引导的从句。 •I doubt if he will e. •I don’t doubt that he will win. • I often doubt whether it is worth spending so much time on homework. •
列连词 so和从属连词 because不能一起使用。 Using both ... and ..., not only ... but (also) ..., either ... or ... and neither ... nor ... both ... and ...、 not only ... but (also) ...、 either ... or ... 和 neither ..
光了 我的早饭。 You’ve eaten up my breakfast。 People with different personalities behave in different ways. Keep all things in good order show off show it / them off •。 Mr wu is patient enough to repeat
________________( ma, full stop) after the ‘if’clause when it is the first part of a sentence. Rules ma , . Unless=If… not Task 2 We can use unless to say that something can only happen or be true in
t advice does Millie’s mother give her? She feels sleepy in class. She should manage her time better and go to bed earlier Millie: Mum, many of my classmates have problems. Mum: Really? How about you
How important is this art form to you? Sandy想以 I like singing best为题写一篇文章来介 绍自己最喜欢的艺术形式，要点： 1. 他一开始不喜欢，因为在许多人面前唱歌很紧张 2. 他十岁时开始喜欢唱歌，因为在朋友的音乐会上表演了节目，得到了大家的认可 …… 3. 现在，他经常用放松的方式来放松自己 …… Sample writing
raph 2 Paragraph 3 What art form do you like best? Are you good at this art form? What do you think of this art form? When did you bee interested in this art form? Do you have any stories about this
河。 而 win的宾语是比赛或奖品等 , 即表示物的名词或代问。 ( ) 3)Our school football team______ the match at last. A. wins B. won C. beat D. beats shows a great interest is very interested to present B adj. 中心的 , 中央的 centre n