Ta có \(A=\frac{1}{2}+\frac{1}{2^2}+...+\frac{1}{2^{100}}\)

\(\)\(2A=1+\frac{1}{2}+...+\frac{1}{2^{99}}\)

\(2A-A=\left(1+\frac{1}{2}+...+\frac{1}{2^{99}}\right)-\left(\frac{1}{2}+\frac{1}{2^2}+...+\frac{1}{2^{100}}\right)\)

\(A=1-\frac{1}{2^{100}}<1\)

=> ĐPCM

4 haha

George, the eldest of four brothers, was brought ……… in London in a Greek shipping family.

A. about

B. up

C. off

D. down

myself

1.Who'll check my teeth?

2.How long did it take Dr Phong to fill Van's tooth?

3.Where does your brother go to?

4.What did Mr Tan do at 5.30 yesterday?

5.Who spent Ha a letter some days ago?

Dịch Anh-Việt

Thai Authorities Express Concern About Superstitious Dolls

Authorities and psychologists in Thailand are expressing concern over the increasing popularity of dolls believed to possess the spirits of child angels. The dolls, known in Thai as luk thep and believed by some to bring their owners good fortune, are purchased for hundreds of dollars and blessed by Buddhist monks. Shops are selling clothing, jewelry and beauty treatments for the dolls. A buffet restaurant in the Thai capital offers children's meals for them. Thailand's Civil Aviation Authority is expected to convene a meeting of airlines and airport operators this week to discuss the surging demand by passengers to take their dolls on board. One domestic airline is already serving drinks and snacks to the dolls if their owners purchase a seat for them. In a memo to its staff, Thai Smile, a subsidiary of the national carrier Thai Airways, explained the dolls could be considered children as they had undergone a spiritual ceremony breathing life into them. Their popularity increased after several Thai celebrities asserted their dolls had brought them luck. If the dolls help their owners feel better then the fad is rather innocuous, according to Nattasuda Taephant, director of psychological wellness at Chulalongkorn University. “But if it crosses the boundary of reality and they believe they can talk to the luk thep doll that would be something concerning in terms of mental health,” she told VOA on Tuesday.

One Direction (commonly abbreviated as 1D) is an English-Irish pop boy band based in London, England. The group is composed of four (formerly five) members: Niall Horan, Liam Payne, Harry Styles and Louis Tomlinson. The group signed with Simon Cowell's record label Syco Records after forming and finishing third in the seventh series of the British televised singing competition The X Factor in 2010. Propelled to international success by social media, One Direction's four albums, Up All Night (2011), Take Me Home (2012), Midnight Memories (2013) and Four (2014) topped charts in most major markets, and generated hit singles including "What Makes You Beautiful", "Live While We're Young", and "Story of My Life". Their fifth studio album, Made in the A.M., was released in November 2015.

Their achievements include five Brit Awards, four MTV Video Music Awards, eleven MTV Europe Music Awards, seven American Music Awards (including Artist of the Year in 2014 and 2015), and nineteen Teen Choice Awards out of nineteen nominations, among many others. According to Nick Gatfield, the chairman and chief executive of Sony Music Entertainment UK, One Direction represented a $50 million business empire by June 2012. They were proclaimed 2012's "Top New Artist" by Billboard.

Warning risk mothers were obese by eating more fish in pregnancy

Children of mothers who eat too much fish during pregnancy, namely more than 3 meals / week, with the risk of obesity in the first year of life compared with children whose mothers ate less fish during pregnancy. US scientists have issued a warning on the study published in the Journal of the American Medical Association (JAMA) on 15 / 2. to draw conclusions on, the scientists of the University Crete has conducted analysis of more than 26,000 data pairs of mother and child in the US and many European countries Au.Ket found children whose mothers ate more than three servings of fish per week during pregnancy with risk of overweight, higher obesity compared to children whose mothers ate fish less. In addition, mothers who ate more fish also increases the risk of other harmful chemicals commonly found in fish, particularly mercury, causing complications for pregnant nhi.Theo scientists, fish and other seafood providing ample nutrition for pregnant women and their unborn babies, to help children develop the brain. However, pregnant women should be noted only eat up to three servings of fish per week, especially those types of fish to eat only natural, not contaminated.