知识可视化是在科学计算可视化、数据可视化、信息可视化基础上发展起来的新兴研究领域，应用视觉表征手段，促进群体知识的传播和创新。常见的知识可视化工具有（）。

A.概念图

B.思维导图

C.认知地图

D.语义网络

根据短文内容和所给中文提示，写出空白处个单词的正确形式，每空限填一词。

It was a   46  (晴朗的) day. We decided to have a picnic outside the   47  (城市). In the morning, we took an   48  (早的) bus there. It was quite a colorful world. there were green trees, orange leaves, red  49   (花). At noon, we reached the place, we   50  (坐) by the river bank and took out a lot of things, such as   51 (面包), orange juice, apples, cakes, eggs and so on.   52 (在…之后) lunch, some classmates played games, some flew kites ,  53  (其他的) painted pictures. But suddenly, it began to rain. Unluckily we didn’t bring umbrellas . We had to take a bus to go back   54  (家) in a hurry. But we still felt very   55  (兴奋) .

What an unforgettable picnic it was!