根据句意，写出括号内所给单词的适当形式。
It's my cousin's ____ (twenty) birthday next week.
The weather in Nanjing is ____ (pleasant) in summer. It's always too hot.
People screamed with____   (excite) when the match began.
He was so tired that he fell____ (sleep) soon after he went to bed.

《马关条约》大大加深了中国半殖民地化程度。该条约中有利于外国人直接利用中国廉价劳动力和原料，剥削中国人民的条款是（   ）

①N₂ ②Mg²⁺  ③SO₂  ④ ⑤

梯田是在坡地上分段沿等高线建造的阶梯式农田。图10所示的庄浪县，位于甘肃省东部，属黄土高原丘陵沟壑区，海拔在1400-2900米，年降水量400-500毫米，该区域经过多年梯田建设，已将92%的坡地改造为梯田，形成了“山顶树木带帽，山间梯田缠腰，地埂牧草锁边，沟台果树围裙，沟底坝库穿靴”的综合开发治理模式，现如今，梯田真正成了庄浪农民的粮屯子和钱袋子。