Read the passage, and choose the correct answer A, B, C or D for each question.

Street Food Shoulder Poles on Saigon streets

Street food shoulder pole is familiar with Saigon people throughout many years. Nowadays it has become a special thing that makes travelers curious. In small areas of District 1 and District 3, we could count more than 100 vendors who earned money using shoulder poles. A shoulder pole, also called a carrying pole, is a yoke of wood or bamboo, used by people to carry a load. The vendors put their goods in two baskets from each end of the yoke.

In the downtown, we can meet young women with their shoulder poles. The baskets are covered with plastic wrap carefully to protect the foods from the street dust. In a tight space ofone basket, she could mix the ingredients and bake the cake on a small charcoal which was defended by carton. The ready cakes were put in other basket.

In the morning or evening, on rainy or sunny day, Saigon streets are marked by shoulder poles of people from different regions of the country, which has become a unique part of Saigon. It has been said that it isn’t hard to live in Saigon if you work hard. With the carrying pole on shoulders, the vendor has turned it into a “store”. The reason is very simple, they don’t have enough money to open a real store. Every day these women continue their journey through Saigon streets under the sun and the rain, selling cheap things or street foods to earn money and feed their children.

1. A shoulder pole____ .

A. is the connection between wood and bamboo

B. used to be called a carrying pole

C. is a bar made of wood or bamboo

D. is used to put goods on street vendor’s shoulders

2. Street food shoulder pole is_____________ .

A. used by street vendors to carry things

B. a characteristic of District 1 and 3

C. used to make foreign travelers curious

D. a way for passer-by to have food

3. All of the following are true about shoulder poles EXCEPT that___________ .

A. street vendors can bake cakes there

B. the two baskets have the same function

C. they can contain enough things to serve some customers

D. they can be protected from dust

4. All of the following are benefits of shoulder poles EXCEPT that ___________.

A. they can help street vendors to sell many things without a store

B. street vendors can support their families with the help of shoulder poles

C. it is a way for street vendors to carry goods around the streets

D. women are marked by unique shoulder poles from different regions

5. The word “yoke” in paragraph 1 is closest in meaning to___________ .

A. a piece of wood that is shaped to fit across a person’s shoulders to carry two equal loads

B. a wooden bar that is connected to the vehicles or loads so that they can be pulled away

C. something that connects two things or people, usually in a way that limits freedom

D. a long piece of wood that is fastened across the necks to pull heavy loads

Bài 2/ 

a) 

ab + ba = 10a + b + 10b + a

            = 11a + 11b

            = 11 . (a + b)             chia hết cho 11

b) 

abc - cba = 100a + 10b + c - ( 100c + 10b + a)

               = 100a + 10b + c - 100c - 10b - a

               = (100a - a) + (10b - 10b) + (1 - 100c)

               = 99a + 0 + (-99)c

               = 99 . [a + (-c) ]  chia hết cho 9

cho x là số thực thỏa mãn: \(-1\le x\le\frac{1}{2}\)

Tìm max M = \(\frac{x}{2}+\sqrt{1-x-2x^2}\)

Cảm ơn ạ

http://olm.vn/thanhvien/xitinpzo

Nếu m < 0 thì tức là \(\sqrt{-m}\)

Mà không có căn bậc 2 cho số âm, thế thì bài này phải là không có giá trị nào của m để thỏa mãn chứ.

Các số đó có dạng ab ta có:

ab + ba = a.10 +b + b.10+ a= ( a.10+a) + (b.10+b)= a.11+b.11

Vì a.11 chia hết cho 11; b.11 cũng chia hết cho 11

=> a.11 + b.11 chia hất cho 11

Vậy lấy 1 số có 2 chữ số cộng với số gồm 2 chữ số ấy viết theo thứ tự ngược lại ta luôn được 1 số chia hết cho 11

(mừn thấy cách của mừn có hơi dài nhưng chắc không sai đou -v-)

Gọi tiếp điểm của tiếp tuyến EF với (O) là H => OH \(\perp\)EF (t/c)
Kẻ OK\(\perp\)AB
mà AB//EF (gt)
từ 3 điều trên => O,H,K thẳng hàng.

Xét tam giác ABC có: Bán kính OA và OB
=> OA = OB = 5cm (gt)
=> \(\Delta ABC\) cân tại O (ĐN) => OK vừa là đường cao, vừa là trung tuyến
=> AK = BK= 4cm
(cậu có thể dựa vào cái ĐL gì mà đường thẳng từ tâm vuông góc với 1 dây cung, tớ tự dưng quên mất)

\(\Delta AKO\) vuông tại K (OK \(\perp\)AB)
=> AO²=AK²+OK² (Pitago)
=> OK = 3cm

HK= OH + OK = 8cm

Chứng minh \(\Delta OEF\)cân tại O => HE = HF (OH vừa là đc, vừa là trung tuyến)

\(\Delta OAK\approx\Delta OEH\) (AK//HE)
=> \(\frac{AK}{HE}=\frac{OH}{OK}\) (t/c) => HE = \(\frac{20}{3}\)

=> EF = \(\frac{40}{3}\)