Unit13 The water planet知識點總復習教案
(6) that可引導一個限制性定語從句，代替某個先行詞(單復數名詞均可)，it和one則不能。例如：① a plane is a machine that can fly. (that指代先行詞machine). 飛機是能飛的機器。② the students that don't study hard will no pass the examination. (that指代students)不努力學習的學生不會通過考試。
(7) it可以代替不定式、動名詞或從句，用作形式主語或形式賓語，而one和that則不能。例如：① it is a great pleasure to see you again. (it代替to see you again)見到你真高興。② it is no use calling him up. (it代替calling him up) 給他打電話是沒用的。③ we found it impossible that they would finis the work in two days. (it代替that they would finish the work in two days) 我發現兩天后完成工作是不可能的。
25. tides provide energy for the ecosystems, but estua- ries are protected from waves and storms by islands, mud or sand. 海潮為生態系統提供能量，河口則由于受到島嶼和泥沙的保護而免遭海浪和風暴的影響。(p.23 第二段 第3－4行)
1) 動詞provide的用法
▲provide意為“提供”“借給”，通常用"provide sb. with sth."或"provide sth. to/for sb."這兩個結構，意為“向某人提供某物”。如：①the book will provide you with the information you need. 這本書會向你提供你所需的情況。 ② we provided him with lodging and food.我們向他們提供食宿。③ the sick were provided with blankets against cold. 給這些病人提供了御寒的毯子。④ his uncle provides money to john. 約翰的伯父給他錢。⑤ the forests provide shelter for wild animals.森林為野獸提供藏身之處。
【注】provide與against連用。如： ① they had already provided against the attack. 他們已做好應付進攻的準備。 ② we have to provide against accidents. 我們必須做好應付事故的準備。
【注】provide的過去分詞可引導條件狀語從句，表示“如果”“只要”。如：① you may keep the book a further week provided that no one else requires it. 只要沒有別人要這本書，你還可借一個星期。② she may come with us provided (that) she arrives in time.如果她及時到達，她可能會和我們一道來。③we'll visit europe next year, provided we have the money. 如果我們有這筆錢，我們明年將去歐洲。
【注】providing也可引導條件狀語從句。如：① you may go out providing you do your homework first. 只要你先把作業做好，你就可以出去。② providing (that) there is no oppositions, we shall hold the sports meet here. 如果沒有人反對，我們將來這里開運動會。
2) protect一詞的用法
▲ protect意為“保護”，后接介詞from或against。如： ① protect the baby's eyes from the sun. 保護孩子的眼睛，不要讓太陽照射。 ② he raised his aln3 t0 protect his face from the blow. 他舉起手臂護住臉，以免被這一拳打中。 ③ put on a thicker coat to protect yourself from the cold. 穿件厚點的外衣以免凍著。④ the eyelashes protect the eyes from dust and dirt. 眼睫毛保護眼睛不讓塵埃和臟東西進去。
【注】動詞protect表示“保護……免受……”，后用from或against都可以，但對于較大的事情如天災等，介詞一般用against。較小的事情用from。如上述例句①－④。