Read the following passage and mark the letter A, B, C, or D to indicate the correct answer to each of the question.

The day after Thanksgiving is the start of the holiday shopping season. Thanksgiving is always on a Thursday, so the day after is a Friday. This day has come to be known as Black Friday. It has been the busiest shopping day of the year since 2005.

Most stores offer great deals on Black Friday. They open their doors in the wee hours of the

morning. They try to attract shoppers with big discounts. Some items like TVs are much cheaper than usual. Stores may even lose money on these items. They hope that shoppers will buy gifts for other people while they are in the store.

Black Friday is a great time to get good deals. The problem is that there are not enough low-priced items to go around. Each store may only have a few. These items are in high demand. People stand in long lines to get such great deals. They may line up hours before a store opens. They may be hoping to get a low price on a TV or laptop, but not everyone who wants one will get one. Some people leave disappointed. The situation can be tense. Some Black Friday events have been Violent. Large, eager crowds have trampled workers. Fights have broken out or people have been cutting in line. People have shot one another over parking spots. But most Black Friday events are safe and fun. Still, if you plan on going, expect large crowds and a bit of shoving.

Which best explains the main idea of the third paragraph?

A. People stand in long lines on Black Friday. 

B. Black Friday is the best time of the year to get good deals. 

C. Black Friday is a really disappointing time of the year. 

D. Black Friday deals are limited and not everyone will get one.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks.

        Quite apart from the economic similarity between present-day automation and the mechanization, (4)_______has been proceeding for centuries, it must also be stressed that even in the United States, automation is by no means the only factor displace people from existing jobs. The increasing number of unneeded workers in recent years has been the result of much more simple and old-fashioned influences:

farm laborers have been (5)       _________out of work by bigger tractors, miners by the cheapness of oil, and railway-men by better roads. It is quite wrong, therefore, to think of automation as some new monster whose arrival threatens the existence of employment in the same way that the arrival of myxomatosis threatened the existence of the rabbit. Automation is one aspect of technological changes (changes in tastes, changes in social patterns, changes in organization) which (6)________in certain jobs disappearing and certain skills ceasing to be required. And even in America, which has a level of technology and output per (7)______much in advance of Britain’s, there is no evidence that the pace of change is actually speeding up. Nevertheless changes in the amount of labor needed to produce a certain output are proceeding fairly rapidly in America - and in (8)_______countries - and may proceed more rapidly in future. Indeed it is one of the main objects of economic policy.

Điền vào số 7

A. human

B. head

C. unit

D. piece

(Hình rối quá bn nhìn đc ko ?)

C/m :

a/ Vì O thuộc đường trung trực của AC (gt)

=> AO = CO (t/c...)

=> tam giác AOC cân tại O (dhnb)

=> \(\widehat{OAC}=\widehat{OCA}\) (t/c tam giác cân) (1)

Xét tam giác AOD \(\left(\widehat{ADO}=90^o\right)\) và tam giác AOF \(\left(\widehat{AFO}=90^o\right)\) có :

AO : cạnh chung

AD = AF (gt)

=> tam giác AOD = tam giác AOF (ch - cgv)

=> \(\widehat{OAB}=\widehat{OAC}\) (2 góc tương ứng) (2)

Từ (1) và (2) => \(\widehat{OAB}=\widehat{OCA}\) (đpcm)

b/ Ta có : \(\left\{{}\begin{matrix}\widehat{OAB}+\widehat{OAM}=180^o\\\widehat{OCA}+\widehat{OCN}=180^o\end{matrix}\right.\) (vì là 2 góc kề bù)

Mà \(\widehat{OAB}=\widehat{OCA}\) (cmt)

=> \(\widehat{OAM}=\widehat{OCN}\)

Xét tam giác AOM và tam giác CON có :

AM = CN (gt)

\(\widehat{OAM}=\widehat{OCN}\) (cmt)

OA = OC (cmt)

=> tam giác AOM = tam giác CON (c.g.c)

c/ +) Vì I thuộc đường trung trực của MO (gt)

=> IM = IO (t/c...) (3)

=> tam giác MIO cân tại I (dhnb)

=> \(\widehat{IMO}=\widehat{IOM}\) (t/c tam giác cân)

+) Vì I thuộc đường trung trực của NO (gt)

=> IN = IO (t/c...) (4)

=> tam giác NIO cân tại I (dhnb)

=> \(\widehat{INO}=\widehat{ION}\) (t/c tam giác cân)

Từ (3) và (4) => IM = IN

Vì tam giác AOM = tam giác CON (cmt)

=> OM = ON (2 cạnh tương ứng)

Xét tam giác IOM và tam giác ION có :

OI : cạnh chung

IM = IN (cmt)

OM = ON (cmt)

=> tam giác IOM = tam giác ION (c.c.c)

=> \(\widehat{IMO}=\widehat{INO}\) (2 góc tương ứng)

Mà \(\left\{{}\begin{matrix}\widehat{IMO}=\widehat{IOM}\left(cmt\right)\\\widehat{INO}=\widehat{ION}\left(cmt\right)\end{matrix}\right.\)

=> \(\widehat{IOM}=\widehat{ION}\)

Mà tia OI nằm giữa 2 tia OM và ON

=> OI là tia phân giác của góc MON (đpcm)

Ai có cách làm ngắn hơn thì góp ý cho mk vs nha ^^

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following question.

A patient is talking to a receptionist at a medical clinic.

Patient: "Can I make an appointment to see the doctor, please?"

Receptionist: “__________”

A. Not at the moment. He can't be disturbed.

B. OK, you will need to check my diary.

C. OK, let me just check the diary.

D. Have a seat and I'll be with you in an hour.

Đề bài đã cho sẵn tam giác ABC cân rồi cần j chứng minh nữa ?

Cho cùng một số mol mỗi chất: (1) phenyl axetat, (2) vinyl axetat, (3) benzyl fomat, (4) metyl metarylat tác dụng hoàn toàn với dung dịch NaOH (dư, đun nóng). Ứng với chất nào thì lượng NaOH phản ứng nhiều nhất? 

A. (2). 

B. (4). 

C. (1). 

D. (3). 

Trên tia đối tia MA lấy D sao cho MA = MD

=> AD = 2AM

Xét tam giác ABM và tam giác DCM có :

MA = MD (cách vẽ)

\(\widehat{M_1}=\widehat{M_2}\left(đđ\right)\)

BM = MC (gt)

=> tam giác ABM = tam giác DCM (c.g.c)

=> AB = CD (2 cạnh tương ứng)

Xét tam giác ACD có : AD < CD + AC (bđt tam giác)

Mà CD = AB (cmt); AD = 2AM (cmt)

=> 2AM < AB + AC

=> AM < (AB + AC) / 2