Locks Caused By Long Lasting SELECT

Hi,

Let's assume the client code call a stored procedure which reads: SELECT * FROM myTable WHERE ID < 100. Let's assume that for whatever reason, the query becomes very slow and takes 60 seconds to complete. This 60 secs, could be the time for the DB engine to fetch all the rows (happening before returning the resultset to client code), or during the transfer of the resultset to client code (slow network throughput).
Question1: could this prevent another user from doing SELECT on myTable? (could be onn different ID or even overlapping the ID between 1 and 100).
Question2: could this prevent another user from performing write (UPDATE/DELETE) on the rows with ID between 1 and 100?
Question3: can another user perform a write (INS, DEL, UPD) on rows outside of the ID between 1 and 100?

Thanks in advance for any help.