All but one of the following is true about the WITH ROLLUP operator. Which one is it?
a
It is part of standard SQL.
b
It adds a summary row for each group specified in the GROUP BY clause.
c
It is coded on the GROUP BY clause.
d
It adds a summary row to the end of the result set.

1. which of the following statements are true about routers and routing on the internet. choose two answers. a. protocols ensure that a single path between two computers is established before sending packets over it. b. routers are hierarchical and the "root" router is responsible for communicating to sub-routers the best paths for them to route internet traffic. c. a packet traveling between two computers on the internet may be rerouted many times along the way or even lost or "dropped". d. routers act independently and route packets as they see fit.