Like most immigrants, he was 22 a better life.
答案：(A) looking for
was + looking for 是過去進行式，表示他當時正在追求更好的生活這個持續進行的狀態；look for（原形）、looked for（過去式）、to look for（不定詞）文法上都不能直接接在 was 後面。
本題大考中心未公布逐題答對率，以下不談數據，只談觀念。
四個選項都是 look for 的變化形，中文都是「尋找」，所以只能靠文法分。這一格的關鍵是空格前面那個 was——它決定了後面只能接哪兩種形態。
先看空格前面：he was ___ a better life。be 動詞後面能接的動詞形態只有兩種：現在分詞（構成進行式）或過去分詞（構成被動）。先看被動行不行：was looked for 的意思會變成「他被找」，但整句要說的是他在追求更好的生活，方向相反，被動可以排除。所以是進行式，填 looking for，構成過去進行式 was looking for（當時正在尋求）——強調那是他當時持續的狀態，正好接得住下一句「所以一八四九年西部發現金礦時，他就加入了淘金的行列」。
look for：原形動詞不能直接接在 was 後面。looked for：若當被動看，語意方向反了；若當過去式看，一個句子不能同時有 was 與 looked 兩個限定動詞。to look for：be + to V 是另一個句型，表示預定或義務（The meeting is to be held tomorrow. 會議預定明天舉行），與這裡的語意不合。
look for（尋找）、be looking for（正在找）、search for（搜尋）、a better life（更好的生活）、be to V（預定、必須）、most immigrants（多數移民）。
When Levi Strauss arrived in the United States from Bavaria, he was only seventeen, poor, and knew very 21 English. Like most immigrants, he was 22 a better life. So, when gold was discovered in the West in 1849, he 23 thousands of others and rushed to California.
24 he planned to open a shop in San Francisco, he took many goods with him, 25 a large quantity of canvas. He hoped to sell 26 as material for tents or wagon covers. Business, however, was not 27 he had expected.
28 , as he sat in a cafe in a small town, he had an idea. He saw a man with a hole in the leg of his trousers and 29 realized what Californians 30 for the rough work they were doing—good, strong trousers!