a stopwatch on his wrist的用法和样例：
- Running with a stopwatch on his wrist, the peerless Paavo captured the 1,500 and 5,000-meter finals within an hour of each other and set Olympic records in both.
- He wore a copper bracelet on his wrist.
- Nathan was treated for minor burns and a gash on his wrist.
- Nathan was treated for minor bums and a gash on his wrist.