Zhang Peng：Hi, Wang Ping. You look fine. How heavy are you?

Wang Ping：I'm 48 kilograms. You are thinner than me, but you look taller than before. How tall are you?

Zhang Peng：I'm 1.6 metres and 45 kilograms.

Wang Ping：Oh, really? You are 0.05 metres taller than me. But I'm 3 kilograms heavier than you. You should eat more.

Zhang Peng：OK, I will. Thank you.

已知双曲线 的左、右焦点分别为 、 ，点 在双曲线的右支上，且 ，则 ＝____．

下图显示了人体有关内分泌腺之间以及与靶细胞之间的调节关系，据图判断下列叙述中正确的是（  ）

若二次根式$\sqrt{x-3}$在实数范围内有意义，则x的取值范围是____.

①关注社会弱势群体，完善社会保障体系  ②正确处理好生产与消费、投资与需求的关系  ③利用国家政权，进行宏观调控  ④倡导企业建立诚信机制