已知向量a，b，c满足$\left|\mathit{a}\right|=\left|\mathit{b}\right|=\mathit{a}\mathbf{·}\mathit{b}\mathbf{=}\mathbf{2}$，$\left(\mathit{a}\mathbf{-}\mathit{b}\right)·\left(\mathit{b}\mathbf{-}2\mathit{c}\right)=0$，则$\left|\mathit{b}\mathbf{-}\mathit{c}\right|$的最小值为（   ）

    西沙群岛一带海水五光十色，瑰丽无比：有深蓝的，淡青的，浅绿的，杏黄的。一块块，一条条，相互交错着。因为海底高低不平，有山崖，有峡谷，海水有深有浅，从海面看，色彩就不同了。

补全对话
Bob: Hi, Bill! I’ve heard you are a football fan, aren’t you?
Bill: Yes.
Bob: (1) ____ 
Bill: Well, when I watch a football game, I feel excited. (2)____ 
Bob: Just a little bit. I’m not good at playing football. (3)____ 
Bill: Oh, I see. Do you have any favourite football stars?
Bob: (4)____ 
Bill: Oh, I like him, too.
Bob: (5) ____ 
Bill: Not much. I’m going to join a football club so that I can play football more.
Bob: That’s a good idea

下列诗句表达的情感不相同的一项是（     ）