Mixed

1234
Across
  1. 4. to add to something in a way that improves it or makes it more attractive
Down
  1. 1. created by computer technology and appearing to exist but not existing in the physical world
  2. 2. barrier that acts as a security system to protect computer systems and networks from outside connections and untrusted networks
  3. 3. unable to think about or pay attention to somethingļ¼›unable to concentrate