5月19日的scmp
If confirmed, it would be Hong Kong's fourth imported swine flu case.Health authorities last night quarantied two housekeeping staff at the hotel and were trying to trace about 50 guests who checked into rooms on the 18th floor during the patient's stay.
點解trace可以跟about??
http://www.ldoceonline.com/dictionary/trace_1
trace唔似vt咩???
vt 唔係跟object而不是preposition??