对精神分裂症的研究表明，精神分裂症的阴性症状可能与以下因素有关（）

A.皮层下边缘系统DA功能亢进

B.皮层下边缘系统DA功能低下

C.5-HT系统功能亢进

D.5-HT系统功能低下

E.皮层内，尤其是前额皮质DA功能相对低下

Dear Wang Ming,

I received your email yesterday. You asked me what I was doing recently. To tell you the truth, I am learning Chinese by myself. I want to go to Beijing this summer, but I don’t know how to learn it well. Could you give me some advice?

I am looking forward to your early reply.

Yours,

David

假如你叫王明，请根据David的来信，用英文给他写一封回信，介绍学习中文的方法，提出你的建议。要点如下：

汉语很有用。

尽可能多地记中国字。

训练听力。

用汉语与你周围的人交流。

多读多写很重要。

不要逐字翻译，可根据实际情况适当增加或删减要点。字数控制在100字以内。

Dear David,

I’m glad to know that you’ll come to Beijing.

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Looking forward to seeing you in Beijing.

Yours,

Wang Ming