步入青春期的信号是（    ）

第一次向世界宣告要建立一个新的普遍性的国际组织，是在1943年10月苏、中、美、英四国共同签署的(　　)

     Mrs Smith is Jim's mother. She loves her family very much. She often buys food, fruit and clothes for Jim and his father. Now many clothes are on sale at a good price.
     Mrs Smith comes to the store and she wants to buy some clothes. They have sweaters in all colors for￥15 each and sports shores for only ￥28.Mrs Smith likes the red sweater and  she buys one for herself(她自己).She buys a pair of sports shores for her son. The T-shirts in the store are just ￥18! She buys a white one for Mr Smith. And that's not all. The socks, in all colors, are ￥2 each. She buys five pairs.

如图，已知点A是双曲线y= $\frac{\sqrt{6}}{x}$ 在第三象限分支上的一个动点，连结AO并延长交另一分支于点B，以AB为边作等边三角形ABC，点C在第四象限内，且随着点A的运动，点C的位置也在不断变化，但点C始终在双曲线y= $\frac{k}{x}$ 上运动，则k的值是____.