在用动物细胞融合技术制备单克隆抗体时，将抗原注射到小鼠体内，可获得
①B淋巴细胞 ②T淋巴细胞 ③效应B淋巴细胞 ④抗体 ⑤记忆细胞(    )

在平面直角坐标系中，若点P的坐标为（﹣3，2），则点P所在的象限是（　　）

假设你叫林洋，收到了你的笔友Susan的一封信，请你给她写一封回信。在信中回答她的问题，提出你的建议，并就此事谈谈你的看法。
Dear Lin Yang,
I have a problem these days. My mother doesn’t allow me to watch TV even on weekends. She says as a middle school student, my job is to study. After I finish my homework, she says, I should read books and watching TV is bad for me. But I think I need a rest and watching TV helps me learn a lot too.
Do you have the same problem? What do you think of my mother’s decision? What should I do?
Yours,
Susan

若实数 $x,y$ 满足 $y=1+\sqrt{1-{\left(x-2\right)}^2}$ ，则 $z=\frac{y}{x+1}$ 的最大值为（  ）

长安城里的“市”是指（   ）