atprep.在；向；达n.基普(老挝货币基本单位)(=att)；[化]砹(极不稳定放射性元素)abbr.密封的(=airtight)abbr.气温(=air temperature)attcin天蚕抗菌蛋白

1. At first I didn't know what had happened.
   起先我不知道发生了什么事。
2. It is easy at first, but we are in deep water now.
   起先很容易，但现在我们陷入了困境。