阅读下面的文言文，完成下列各题。

虹

    世传虹能入溪涧饮水，信然。熙宁中，予使契丹，至其极北黑水境永安山下卓帐^①．是时新雨霁，见虹下帐前涧中。予与同职扣涧观之，虹两头皆垂涧中。使人过涧，隔虹对立，相去数丈，中间如隔绡縠^②．自西望东则见，盖夕虹也。立涧之东西望，则为日所铄，都无所睹。久之，稍稍正东，逾山而去。次日行一程，又复见之。

    孙彦先云：虹乃雨中日影也，日照雨则有之。

（选自沈括《梦溪笔谈》）

【注】①卓帐：竖立帐篷。②绡縠（xiāo hú）：一种丝织品。

A: I need to lose some weight. My clothes don't fit anymore.____

B: Well, instead of watching TV all day, you could do more exercise.

A:____

B: Like cycling, or you could work out at the gym.

A: I don't have time.____

B: OK, then you could change your diet.____

A: You mean no more hamburgers! Oh no!

B: OK._____

读图，判断图中A地在B地的方向是（    ）

____ ____ favourite subject?