Do you remember the one before her?"  
Can you recall who came before her?
There was no one that came before her.
There is an ambulance.
She's unseen and invisible.
Most doctors do not feel stressed about the requirements of professional discretion at all.
A group of African Americans are running down a street.
For members of the president's own party to vote against him, the case against him should be strong enough to justify such a vote.
The codes of custom and conduct fell into obscurity in the country.