why I have unmatched nets?

[Allen]

I am making the layout of a circuit using layout XL and I have the
following several issues unclear.
1. Can I pick up one component(or a few components) from the schematic
and copy them in the layout window if I have lots of identical
components?

2. When I did LVS check I got lots of unmatched nets and it tells me
that those nets should have 2 connections, I check over the schematic
and layout, they do look like they have two connections, what could be
the problem? Thanks.

Regeards.
Allen