If you do not use your arm or your legs for some time, they become weak; when you start using them again, they slowly become strong again. Everybody knows that. Yet many people do not seem to know that memory works in the same way. When someone says that he has a good memory, he really means that he keeps his memory in practice by using it. When someone else says that his memory  is poor, he really means that he does not give it enough chance to become strong. If a friend says that his arms and legs are weak, we know that it is his own fault . But if he tells us that he has a poor memory, many of us think that his parents are to blame , and few of us know that it is just his own fault. Have you ever found that some people can't read or write but usually they have better memories? This is because they cannot read or write and they have to remember things they cannot write down in a little notebook. They have to remember days, names, songs and stories; so their memory is the whole time being exercised. So if you want to have a good memory, learn from the people: Practice remembering. Some people can't read or write, but they usually have better memories, because   _  .
they have save much trouble they have saved much time to remember things they have to use their memories all the time they can't write everything in a little notebook
Question: If you do not use your arm or your legs for some time, they become weak; when you start using them again, they slowly become strong again. Everybody knows that. Yet many people do not seem to know that memory works in the same way. When someone says that he has a good memory, he really means that he keeps his memory in practice by using it. When someone else says that his memory  is poor, he really means that he does not give it enough chance to become strong. If a friend says that his arms and legs are weak, we know that it is his own fault . But if he tells us that he has a poor memory, many of us think that his parents are to blame , and few of us know that it is just his own fault. Have you ever found that some people can't read or write but usually they have better memories? This is because they cannot read or write and they have to remember things they cannot write down in a little notebook. They have to remember days, names, songs and stories; so their memory is the whole time being exercised. So if you want to have a good memory, learn from the people: Practice remembering. Some people can't read or write, but they usually have better memories, because   _  .
A. they have save much trouble
B. they have saved much time to remember things
C. they have to use their memories all the time
D. they can't write everything in a little notebook
Answer: