重點講解：
1. set out to do sth. 開始；著手；
We set out to find the truth behind the mystery.
我們開始著手揭開謎團背后的真相ZDVb-|A(ZfOed+I-k@^9。
2. make up 組成；構成；
North Africans make up the largest and poorest immigrant group in the country.
北非人構成了該國最大的、也是最貧困的移民群i.luTIpxxkc]|o^_YUS-。
3. break down （使）（物質）分解；
The oil is attacked by naturally occurring microbes which break it down.
原油受到了自然產生的分解油類物質的微生物的侵蝕*9iw4De(M98Lu。
4. cut down 消減；縮減；裁減；
Car owners were asked to cut down travel.
要求車主們減少駕車出行的次數k+!Sq3^h,a4])YK。