-5
This will return -5 as the result. The + operator functions as a unary plus operator, which means that it performs no operation on the value it preceeds.

DDL triggers
DDL triggers cannot be signed, but all the other objects can.

The latency between transaction commits at the publisher and subscriber exceeds the warning level.
This status can actually mean two different things. Either the latency between the commit of a transaction at the publisher and the same commit at the subscriber is exceeding some level in a transactional level or not enough rows are being processed in a merge replication scenario.

Blocking Transformation
The Sort component is a blocking transformation meaning that it needs all rows in order to perform its function.

Add, string concatenation, unary plus
The three functions are Add, String Concatenation, and Unary Plus.

This agent reads the subscriber logs and moves changes back to the publisher.
This agent is used when the queued update model is chosen with transactional replication. It moves changes from the subscribers back to the publishers.

2 and 2
Each select statement actually returns 2 rows. You can use this script to check this:
create table mytable
( id int identity(1,1)
, mychar varchar(20)
)
go
insert mytable select null
insert mytable select ”
insert mytable select ‘ ‘
go
set ansi_nulls on
set ansi_null_dflt_on on
select * from mytable
where mychar is not null
select * from mytable
where mychar <> ” and mychar is not null
select * from mytable
where mychar <> ‘ ‘ and mychar is not null
select * from mytable where mychar = ”
select * from mytable where mychar = ‘ ‘
set ansi_null_dflt_on off
set ansi_nulls off
go
drop table mytable

The type of lock being held by an application that requested it.
This command returns the lock mode held by an application that was requested with the sp_getapplock procedure.

insert mytable select ”
insert mytable select ‘ ‘
select * from mytable where mychar = ”
select * from mytable where mychar = ‘ ‘

The DCM tracks changes. The differential backup reads the extents from this structure.
A differential backup uses the Differential Change Map to determine which extents have changed and need to be include in the backup. This greatly speeds the differential backup process.

The angle between the x-axis and a ray.
This is a mathematical function that returns the angle between the positive x-axis and the ray that passes through the two coordinates passed in. The angle is in radians.