Without altering the meaning of text 6A6BBB, the expression “covert signals” (l.3) could be replaced by Without altering the meaning of text 6A6BBB, the expression “covert signals” (l.3) could be replaced by

Without altering the meaning of text 6A6BBB, the expression...

Q925052

Without altering the meaning of text 6A6BBB, the expression “covert signals” (l.3) could be replaced by

hidden signals.

convergent signals.

coverage signals.

open signals.