农业包括种植业、畜牲业、林业、渔业四大部门。请在图中A、B、C、D四地合理安排四大部门。

①胸腺在免疫中的作用是先分化出造血干细胞，进而分化出T细胞　

②过敏反应是指已免疫的机体在再次接受相同抗原的刺激时所发生的反应　

③吞噬细胞、T细胞、B细胞、记忆细胞、浆细胞均能识别抗原　

④一种抗原只能与相应的抗体或效应T细胞发生特异性结合　

⑤自身免疫病和艾滋病都是机体免疫功能不强或缺陷造成的

读下列“四个半岛略图”，回答下面小题

语法填空

    ____ is well known, optimism(乐观)plays an important role in one's life. Although we are facing many difficulties, we should keep optimistic. Optimism is a mental(精神的)attitude or world view and it means expecting ____ best possible result from any given situation.

    I did ____ (poor) in English in the past, but I never gave up struggling(搏斗). All my families, teachers and friends encouraged ____ (I) and they taught me a lot of ____ (use) ways of learning English. I ____ (keep) practicing as they told me to do. I listened to English news and songs and I read interesting English stories. At weekends, watching some English movies was another good way to make my English better. ____difficulties I came across, I tried my best to work them out. I believe in myself, ____ (believe) that hard work would finally pay off. Gradually, I make progress in my English. Nowadays, I can remember English words ____ (easy) and use them freely when communicating with foreigners.

    Thanks to optimism, I have become one of the top English ____ (learn) in my school now.