[单选题]涡流是一种( )现象。
A.电磁感应
B.电流热效应
C.化学效应
D.电流化学效应

某城区为了举办残奥会而成立了一家专门为附近社区智障人士提供服务的机构。该机构的活动设施比较健全，另有三名专职人员负责活动和管理。该机构的学员年龄参差不齐，智障程度也不尽相同。在残奥会期间，该机构的活动内容比较丰富，形式也多样化，深受学员和家长的喜爱。但随着残奥会的闭幕和一名专职人员的离职，该机构的活动内容变得单一，且流于形式，致使康复设施搁置，前来提供服务的志愿者大大减少，学员也没有多大的积极性。这种状况让学员家长非常忧虑。

[问题]

假如你是该机构的社会工作者，请你针对目前情况设计一份社区服务方案。

Some people give up trying to learn a foreign language. It can seem too much like hard work. But the problem comes when they go abroad on holidays and find they cannot communicate. How do they ask the way, order a cup of coffee, or ask the price of something
Keith Chiwick thinks he has the answer to this problem. "I have got a machine which talks in different languages. I feel that I could go to any country in the world and converse with any foreigner," he says. Keith is an inventor. His invention is an electronic machine which produces phrases in four different languages, French, German, Italian and English. Unlike the phrase books, this machine has a voice. It looks like a cassette recorder.
Imagine you want to say, "What time is the next train for Munich" in German. First, you find the right card for that question. Each card has four strips of tape on it, one for each language. The cards are small, seven by nine centimeters, and each
A. He wants to put his products into the market.
B. He wants to run an electronics company.
C. He wants to sell his idea of the machine to an electronics company.
D. He wants to go to Germany with his new machine.