291. 首先，你必須努力工作。
[誤] At first, you must work hard.
[正] First, you must work hard.
注：at first 指“起初，開始的時候”，如：At first I found this question very difficult, but finally I managed to
answer it（一開始我覺得這個問題很難回答，不過最后我還是答出來了）；first 才是指“首先”。又如：First, let me introduce myself（首先，請允許我介紹一下我自己）。
[誤] At first, you must work hard.
[正] First, you must work hard.
注：at first 指“起初，開始的時候”，如：At first I found this question very difficult, but finally I managed to
answer it（一開始我覺得這個問題很難回答，不過最后我還是答出來了）；first 才是指“首先”。又如：First, let me introduce myself（首先，請允許我介紹一下我自己）。