It was my first day in this beautiful tropical city. 31 I was walking to the beach, a stranger came up to me and tried to shake my hand.
答案：(A) As
As 在這裡表示「當……的時候/正當」，表示兩個動作同時發生（我走向海灘的時候，一個陌生人走過來）；But（但是）、Though（雖然）、For（因為）都不符合這裡的同時性語意。
本題大考中心未公布逐題答對率，以下不談數據，只談觀念。
四個選項都能翻成中文的「當、但是、雖然、因為」，光比意思會在 As 與 Though 之間猶豫。這一格先用形態刷掉一半，剩下的才輪到語意。
先看結構：空格後面是 I was walking to the beach（一個完整的子句），逗號之後 a stranger came up to me and tried to shake my hand 又是一個完整的主要子句。兩個完整子句要接在一起，空格要的是從屬連接詞，而且它得放在從屬子句的最前面。For 與 But 先出局，兩個都是對等連接詞：But 連接的是地位相同的兩個部分，不會造出「從屬子句加主要子句」這種結構；For（因為）引出的是前面那句話的理由，位置只能在後面，而空格在整句的最前面，前面根本還沒有東西讓它解釋（同判準：91 年第 24 題、90 年第 21 題）。剩下 As 與 Though，用語意分：「我正走向海灘」與「一個陌生人走過來」之間沒有互相牴觸的意思，不是讓步；兩件事是同時發生的——空格後面用的是過去進行式 was walking，正好當「正當我在走的時候」這個背景，前景則是陌生人突然出現。這是 As 的「當……的時候」。順帶把 as 在題庫裡考過的身分整理一下：本題是「當……時」；91 年第 24 題是「隨著」；94 年第 18 題是介系詞「以……的身分」。先看後面接的是子句還是名詞，再看語意，就分得出來。
Though（雖然）：讓步要求前後兩件事互相牴觸，本句沒有。But（但是）：對等連接詞，不能放句首帶出一個從屬子句再接主要子句。For（因為）：它引出的是前一句的理由，位置只能在後面。
as ＋ 子句（當……的時候）、come up to sb（走向某人）、shake hands with sb（與某人握手）、walk to the beach（走向海灘）、a tropical city（熱帶城市）、the first day（第一天）。
It was my first day in this beautiful tropical city. 31 I was walking to the beach, a stranger came up to me and tried to shake my hand. "Don't you remember me, my friend?" he said. But I couldn't 32 his face at all. I didn't know a soul in the city. I had just arrived by plane and still had jetlag. "I 33 you at the airport. I work there at the customs. How are you enjoying our beautiful city?" I couldn't remember him but I was too 34 to tell him. He was so friendly.
35 he offered to take me to his uncle's seafood restaurant, just by the beach. I thanked him 36 but he insisted that we should go there for dinner. "You'll love the seafood there," he 37 me. "And it will be a dinner to remember."
So we went to the restaurant and sat by a window 38 the bay. The dinner was great indeed, but the coffee they served was quite different. In fact, it tasted very strange...
Anyway, it was not 39 10 o'clock the next morning that I finally woke up. But I had no idea where I was. All my money was 40 and my "friend" had even taken my watch and my shoes!