There are hundreds of national parks and wildlife areas in Africa that you can travel to. Here are the top four travel destinations in Africa: Tanzania----Serengeti National Park During the annual migration , when the wildebeests  and zebras pack up and leave their living areas to find fresher ones, the Serengeti is an astonishing place to be. It's a very good travel spot in Africa at other times of the year too, but the migration has been ranked by many as one of the wonders of the natural world. Kenya----Masai Mara National Park If you want to see the big cats, this wildlife park is the best of the best. Lion, leopard and cheetah abound and they are relatively easy to spot because of the grassland vegetation which means you get good views for miles around. Another big plus is the fact that going off road is allowed and it is a big advantage because the animals will rarely oblige you and stay next to the major roads. South Africa-Kruger National Park For the variety of species no other places in Africa can come close to the Kruger Park. And because it is so large it has a number of different ecosystems that you can pass through in your search for animals and birds. It is one of the best managed parks in Africa and the accommodation is well-equipped, too. Zambia-South Luangwa National Park South Luangwa is a diamond in the rough, just waiting for enough exposure to bring it to its rightful place in the crown of prime Africa trips. It has been regarded as one of the best places in Africa to see the special leopard and it is the birthplace of the walking travel. In which parks can visitors see leopards? A) Serengeti National Park and Krunger National Park. B) Masai Mara National Park and South Luangwa National Park. C) Krunger National Park and South Luangwa National Park. D) Serengeti National Park and South Luangwa National Park.
B
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On July 1 at exactly 7:59:59, Bejing time, the world' s atomic clocks will pause for a single second, or, more precisely, change to the unusual time of 7:59:60. The addition of a leap second   , is to keep our clocks in time with the slowing of Earth' s rotation   and astronomical time as measured by the sun. Just one extra second could affect the way computers and websites work, however. When the last leap second was added back in 2012, the community website Reddit crashed. For Reddit, the problem was that a Linux system got confused when it checked the network time and found an extra second. Speaking to Wired about the problem back in 2012, Linux creator Linus Torvalds commented:"Almost every time we have a leap second, we find something. It' s really annoying, because it' s code that is almost never used, and thus not tested by users under their normal conditions. " Companies have thought of their own solutions, and Google' s"leap smear"may be the best- known example. As company engineer Christopher Pascoe explains in a blog post, companies usually try to turn back the clocks by one second at the end of the day so that they play that second again. However, Pascoe believes this creates problems. He asked:"Does email that comes in during that second get stored correctly?"Google has a solution: Cut the extra second into milliseconds and then put these tiny amounts of time into the system throughout the day."This means that when it became time to add an extra second at midnight."Says Pascoe."Our clocks have already taken this into account over the course of the day." For many companies without Google' s money, however, the leap second will likely still cause some crashes. Why do we need to add a leap second? A) To change the world' s atomic clocks. B) To keep atomic clocks in time with the world' s computers. C) To keep atomic clocks in time with the slowing of Earth' s rotation. D) To record the changes to astronomical time.
C
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The end of my sophomore year was approaching.Mom called me at the dorm one evening during the last week of May.My summer break would be spent with grandma and grandpa, helping out around their farm.The arrangement made good sense to all the family.I wasn't fully convinced of that myself but guessed it was just one summer.Next year would be my little brother's turn. I arrived late that afternoon.Grandma had fixed more food than the three of us could possibly eat.She loved me entirely too much.The next morning, Grandpa fixed breakfast for the two of us. He told me Grandma had tired herself out yesterday and was going to rest in bed a little longer.I made a mental note to myself to not ask her to do things for me while I was there.I was there to help, not be a burden.               Weeks passed.I gradually settled into a routine of daily work with Grandpa.In the evenings I usually read or talked with Grandma.She never grew tired of hearing about college or anything I was involved in.She told me stories about her childhood, family and the early years after she and Grandpa had married.               The last Saturday in June, Grandpa suggested going fishing.We hadn't expected what we saw when we got to the pond that morning: One of the swans was dead.Grandpa had given the pair of swans to Grandma on their 50th anniversary."Why don't we see about buying another one," I suggested, hoping the situation could somehow be righted.Grandpa thought for a few moments before answering.               He finally said, "no...it's not that easy, Bruce.You see, swans mate for life." He raised his finger to point, holding the fishing pole in his other hand."There's nothing we can do for the one that's left.He has to work it out for himself." A few days later, we drove by the pond while doing our morning check on the cows.We found the other swan lying near the same spot we had found the first one.It, too, was dead.               The month of July started with me and Grandpa putting up a new stretch of fence.Then July 12 came.That... Which of the following can be the best title for the passage? A) Mate For Life B) Unforgettable Summer Break C) Death of Swans D) Everlasting Love Story

A
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