Read the following article and select the best answer. Article: Can people change their skin colour without suffering like pop king Michael Jackson? Perhaps yes. Scientists have found the gene that determines skin colour. The gene comes in two versions, one of which is found in 99 per cent of Europeans. The other is found in 93 to 100 per cent of Africans, researchers at Pennsylvania State University report in the latest issue of Science. Scientists have changed the colour of a dark-striped zebra fish to uniform gold by inserting a version of the pigment gene into a young fish. As with humans, zebra fish skin colour is determined by pigment cells, which contain melanosomes . The number, size and darkness of melanosomes per pigment cell determines skin colour. It appears that, like the golden zebra fish, light-skinned Europeans also have a mutation in the gene for melanosome production. This results in less pigmented skin. However, Keith Cheng, leader of the research team, points out that the mutation is different in human and zebra fish genes. Humans acquired dark skin in Africa about 1.5 million years ago to protect bodies from ultra-violet rays of the sun, which can cause skin cancer. But when modern humans leave Africa to live in northern latitudes, they need more sunlight on their skin to produce vitamin D. So the related gene changes, according to Cheng. Asians have the same version of the gene as Africans, so they probably acquired their light skin through the action of some other gene that affects skin colours, said Cheng. The new discovery could lead to medical treatments for skin cancer. It also could lead to research into ways to change skin colour without damaging it like chemical treatment done on Michael Jackson. Question: We can infer from the passage that _ . - people like to change their skin colour - a mutation in the gene for melanosome production is different in human and zebra fish gene - people will be able to change their skin colour without chemical treatment in the future - skin cancer can be cured now
people will be able to change their skin colour without chemical treatment in the future

Read the following article and select the best answer. Article: Valentine's Day was coming. Helen felt hurt and lonely because this was her first Valentine's Day after the divorce . Helen's twelve-year-old son, Jack, looked at his mother, knowing that this was a difficult time for both of them. In order to make his mother happy, he prepared a present, and handed it to her on Valentine's Day. It was a beautiful gift package .Helen couldn't believe what was happening. She opened it and took out a lovely card and a small box. "Now," he said, "read the card." It read as follows: "I know that this isn't easy for you because it has been a hard year for both of us. I know that Valentine's Day is a special day for people in love. I want you to know that I love you. I know that Valentines are supposed to get chocolate. I went to the store today to buy some for you. Luckily, I got the last piece. I told the clerk it was just perfect." Helen stood there for a moment and looked at her son. Her eyes sparkled in the light as tears formed in each corner. Jack knew he had done the right thing. Slowly she opened the small box, careful not to tear the paper. She would never forget the moment. She found a chocolate heart that was broken into pieces along with a note: "I am so sorry that Dad left us, Mom. And all you were left with was a broken heart. But I just want you to know we still have each other. Happy Valentine's Day! Your son, Jack" Question: Jack wrote a card to his mother in order to _ . - express he missed his father - explain why he felt lonely - ask her to give him some money - show his love to her
show his love to her

Q: Read the following article and select the best answer. Article: Franz Schubert was a well-known musician in the world. But he lived a very hard life and often went hungry. One day, being very hungry, he went into a small restaurant in Vienna, hoping he might meet some friends there. He looked around and saw nobody he could borrow any money from. Then his eyes fell on a paper on one of the tables. In it was a little poem. He took the paper with the poem. After he composed a piece of music for the poem, he took his work to the owner of the restaurant. He only received a dish of beef and potato for it. thirty years after his death, this manuscript by Schubert was sold for 40 00c francs. it was his famous berceuse . Question: From the passage we didn't know that _ . - where Schubert composed his famous berceuse - why Schubert composed his famous berceuse - whether it was hard for Schubert to make a living - who bought his famous berceuse for 40 000 francs
A: who bought his famous berceuse for 40 000 francs

Q: Read the following article and select the best answer. Article: When Taking an Uber-Should You Tip or Not? Taking an Uber car may no longer be a direct driver-passenger and guilt-free experience. The ride-sharing experience is about to get awkward. With the wide application of the Internet, Uber, a new approach to your destination instead of taking an ordinary taxi, has become more popular recently. However, benefits won't come without its fair share of drawbacks. Uber drivers are a part of the so-called sharing economy: They use their own vehicles, receive customer reviews via the app's five-star rating system and make their own hours. Unlike other services, Uber claimed that drivers all over the country could clearly alert customers that tipping is not included. Those drivers that expect to be tipped can make their wishes known. But the company is holding to its official no-tip-required line, according to its website. "Once you arrive at your destination, your fare is automatically charged to your credit card on file--There's no need to tip." Although drivers value their independence--the freedom to push a button rather than punch a clock, lack of a clear policy, however, leaves Uber drivers in a vulnerable position: If they ask a customer for a tip or put up a sign, that customer could give the driver a low star-rating, and the driver could finally be _ from the app. But has the company done a good job working with customers? Some observers say that this new grey area for tipping will create awkwardness about whether they should tip or not--something most Uber customers have not had to deal with until now. Uber did not respond to customers' comment, just leaving their rating in the air(ignoring it). Providing an option to tip on an app sends a clear message to customers to reach into their pockets. Nearly 30% people would be more likely to leave a tip if they were presented with a "no tip" button, according to Guinn's 2015 survey of roughly 500 people. When people are presented with three tip choices--20%, 25% or 30%--they're more likely to choose the middle option... Question: Compared with taxi drivers, Uber drivers _ . - enjoy more freedom and choices - support the company's practice - clock up the miles while driving - receive customers reviews directly
A: enjoy more freedom and choices