下列各种灾害在形成、发展、致灾上，彼此之间有着密切关联性的是（   ）

①____n. 允许  ②____v. 猜测   ③____n. 协议

④ ____n. 关系  ⑤____v. 交流  ⑥____v. 争吵

⑦____n. 云  ⑧____adj.年纪较大的 ⑨____adv.代替

⑩____pron. 任何

There’re 24 h____  in a day .
What’s his j____ ? He’s a teacher .
Don’t l____ to music in class .
Jackie Chan is a very s____  actor . He’s in many movies .
S _____  is the first day of a week .
My mother has lots of work to do every day . She’s very b____ 
Beijing is the capital （首都）of C____ .
I can’t a____  that question. It’s too difficult
Best w____ to you , Miss Jin . 
Kate , please w____  your name on the card .

如图，一光滑的轻滑轮用细绳OO′悬挂于O点；另一细绳跨过滑轮，其一端悬挂物块a，另一端系一位于水平粗糙桌面上的物块b．外力F向右上方拉b，整个系统处于静止状态．若F方向不变，大小在一定范围内变化，物块b仍始终保持静止，则（  ）