由直线$x=0$，$x=\frac{2\pi }{3}$，$y=0$与曲线$y=2\sin x$所围成的图形的面积等于(  )

阅读《唯一的听众》选段，回答文后的问题。

    ①当我感觉到身后有人而转过身时，吓了一跳，一位极瘦极瘦的老妇人静静地坐在一张木椅上，双眼平静地望着我。我的脸顿时烧起来，心想这么难听的声音一定破坏了这林中和谐的美，一定破坏了这位老人正独享的幽静。

    ②我抱歉地冲老人笑了笑，准备溜走。老人叫住我，说：“是我打搅了你吗？小伙子。不过，我每天早晨都在这里坐一会儿。”有一束阳光透过叶缝照在她的满头银丝上，“我猜想你一定拉得非常好，只可惜我的耳朵聋了。如果不介意我在场的话，请继续吧。”

    ③我指了指琴，摇了摇头，意思是说我拉不好。

    ④“也许我会用心去感受这音乐，我能做你的听众吗？就在每天早晨。”

    ⑤我被这位老人诗一般的语言打动了，我羞愧起来，同时暗暗有了几分信心。嘿，毕竟有人夸我了，尽管她是一个可怜的聋子。我于是继续拉了起来。以后，每天清晨，我都到小树林去练琴，面对我惟一的听众，一位耳聋的老人。她一直很平静地望着我。我停下来时，她总不忘说一句：“真不错。我的心已经感受到了。谢谢你，小伙子。”我心里洋溢着一种从未有过的感觉。

    ⑥很快，我就发觉我变了，家里人也流露出一种难以置信的表情。我又在家里练琴了，从我紧闭门窗的房间里，常常传出基本练习曲。若在以前，妹妹总会敲敲门，装出一副可怜的样子，说：“求求你，饶了我吧!”而现在，我已经不在乎了。当我感觉到这一点时，一种力量在我身上潜滋暗长。我不再坐在木椅子上，而是站着练习。我站得很直，两臂累得又酸又痛，汗水早就湿透了衬衣。同时每天清晨，我还要面对一位耳聋的老人尽心尽力地演奏；而我唯一的听众也一定早早地坐在木椅上等我了。有一次，她竟说我的琴声能给她带来快乐和幸福。我也常常忘记了她是个可怜的聋子。

郭靖和杨康是《射雕英雄传》中的两个重要人物。他们名字中的“靖”、“康”与下列历史事件有直接联系的是（    ）

下列说法正确的是（　　）

    Currently offered by some famous universities, MOOCs are attractive to people who do not have the financial resources to meet the growing costs of university education, or who do not have formal qualifications. They also allow participants to study at their own pace.

    The potential for MOOCs to deliver education is obviously vast—they could be considered as a huge step forwards in widening participation. They also have the potential to provide a unique window on universities that offer popular and valuable courses, they may attract some participants to register for formal fee-paying programmes at the same or other universities and are likely to promote new ways of on-line education.

    However, it is still very early days for MOOCs. The quality of the education provision is highly variable, with many courses offering only recordings of lectures, and delivery is particularly difficult in some special fields that require practical classes, research projects or extensive library access. Besides, wider engagement with participants requires very considerable resource. Even limited feedback or examination becomes a major task if there are several thousand students in the class.

Considering the challenges, some people argue MOOCs will soon evaporate (蒸发). But they certainly provide good opportunity for widening higher education, are a means of raising awareness of universities to audiences of tens or hundreds of thousands, and are well worthy of serious consideration.