问题
单项选择题
RAM具有的特点是______。
A.海量存储
B.存储在其中的信息可以永久保存
C.一旦断电,存储在其上的信息将全部消失且无法恢复
D.存储在其中的数据不能改写
答案
参考答案:C
解析: 随机存储器(RAM)的特点是读写速度快,最大的不足是断电后内容立即丢失,加电后也不会自动恢复,即具有易失性。
RAM具有的特点是______。
A.海量存储
B.存储在其中的信息可以永久保存
C.一旦断电,存储在其上的信息将全部消失且无法恢复
D.存储在其中的数据不能改写
参考答案:C
解析: 随机存储器(RAM)的特点是读写速度快,最大的不足是断电后内容立即丢失,加电后也不会自动恢复,即具有易失性。
阅读理解。 |
Everyone may know tree rings tell us how old a tree is. But do you know they can tell us what the weather was like? A tree grows well in a climate (气候) with lots of sunlight and rainfall (雨量). And little sunshine or rainfall limits (限制) the growth of a tree. We can see the change of climate by studying the tree rings. For example, to find out the weather of ten years ago, you can count the rings of a tree from the outside to the inside. If the tenth ring is far from the eleventh ring, then we are sure that it was sunny and rainy most of that year. If it is near to the eleventh ring, then the climate of that year was bad. |
1. Tree rings can tell us not only the ___ of a tree but also the ___. |
[ ] |
A. age; weather B. rainfall; sunshine C. age; rainfall D. sunshine; age |
2. ___ in good climate. |
[ ] |
A. Tree rings grow far from each other B. Tree rings become thinner C. Trees don't need sunshine or rainfall D. Tree rings grow near each other |
3. From the passage we know, trees need ___ to grow. |
[ ] |
A. sunlight and tree rings B. rainfall and rings C. sunlight and rainwater D. water and insects |
4. According to the passage, if the thirty-first ring is near to the thirty-second ring, the climate of that year was ___. |
[ ] |
A. sunny B. rainy C. bad D. unknown |
5. If you want to find out the weather of twenty years ago, you should study__ of a tree from the outside to the inside. |
[ ] |
A. the twentieth ring B. the tenth ring C. the ninth ring D. the twenty-first ring |