细胞分裂时，遗传物质的变化是（　　）

某中学组织学生去福利院慰问，在准备礼品时发现，购买1个甲礼品比购买1个乙礼品多花40元，并且花费600元购买甲礼品和花费360元购买乙礼品的数量相等．

    You may be surprised to learn that English gets 30 to 45 percent of its words from French. The reason goes back to the year 1066, when Norman forces invaded（入侵）what is now Britain. The Normans were from northern France and spoke French. During the Norman occupation, French became the language of England's rulers and wealthy class. This lasted for more than 300 years. Other people in England continued to speak English during this period.

    Over time, the two languages combined and shared words. Some researchers believe that about 10,000 French words eventually entered the English language. However, although English took many French words, their meanings have not always stayed the same. Sometimes the differences in meanings can be very important, and lead to funny or strange situations if the words are used in the wrong way.

    Take, for example, the French word college. In English, college can often be used in place of the word university, or sometimes as a school within a university. However, in French, college actually means “middle school”, or the level of schooling for students in grades five or six through eight.

    There are many other similar words in the two languages with completely different meanings. In English, the word chat is a verb which means “to talk casually”; but in French, the word chat is the word for an animal: a cat.

    If an English speaker says someone is jolly, that means they are cheerful or friendly. But in French, jolie means someone is good-looking or pleasant to look at. In any case, both are nice things to say to someone.

    Have you ever found yourself in this situation：You hear a song you used to sing when you were a child-a bit of nostalgia（怀旧）or "blast from the past，"as we say．But it is not a distant childhood memory．The words come back to you as clearly as when you sang them all those years ago．

    Researchers at the University of Edinburgh studied the relationship between music and remembering a foreign language．They found that remembering words in a song was the best way to remember even one of the most difficult languages．

    Here is what they did. Researchers took 60 adults and randomly divided them into three groups of 20．Then they gave the groups three different types of "listen-and-repeat" learning conditions．Researchers had one group simply speak the words．They had the second group speak the words to a rhythm，or beat．And they asked the third group to sing the words．

    All three groups studied words from the Hungarian language for 15minutes．Then they took part in a series of language tests to see what they remembered．

    Why Hungarian，you ask ? Researchers said they chose Hungarian because not many people know the language．It does not share any roots with Germanic or Romance languages，such as Italian or Spanish．After the tests were over，the singers came out on top．The people who learned these new Hungarian words by singing them showed a higher overall performance．They did the best in four out of five of the tests．They also performed two times better than those who simply learned the words by speaking them．

    Dr．Katie Overy says singing could lead to new ways to learn a foreign language．The brain likes to remember things when they are contained in a catchy 3，or memorable 4，tune 5．

    Dr．Ludke said the findings could help those who struggle to learn foreign languages．On the University of Edinburgh's website Dr．Ludke writes，"This study provides the first experimental evidence that a listen-and-repeat singing method can support foreign language learning，and opens the door for future research in this area．"