如图所示，ACB是一光滑的、足够长的、固定在竖直平面内的“∧”形框架，其中CA，CB边与竖直方向的夹角均为θ．P，Q两个轻质小环分别套在CA，CB上，两根细绳的一端分别系在P，Q环上，另一端和一绳套系在一起，结点为O．将质量为m的钩码挂在绳套上，OP，OQ两根细绳拉直后的长度分别用l₁、l₂表示，若l₁＜l₂，则下列说法正确的是（   ）

    Hello ,my friends.I 1_free this Sunday. We have no classes. I would like 2 out tor a picnic with my family on the farm. My mother and I do some shopping3 the morning. My mother buys some4,like bread and chicken . I buy5bags of milk. A bar of chocolate needs 11 yuan , but I buy five 6 50 yuan. Bananas are my7 I take a lot of bananas with 8.On the farm we see many rabbits. They are very9.I like them very much. We are all 10  on that day.

“这真是空前未有的亡国条约！它使全中国都为之震动。从前我国还只是被西方大国打败过，现在竟被东方的小国打败了，而且失败得那样惨，条约又订得那样苛刻，这是多么大的耻辱啊！”材料中的“亡国条约”指的是（    ）