What is the correct way to complete the sentence below?Today black spots or shad...

Questão de Inglês da banca Marinha aplicada no concurso ESCOLA NAVAL (2009). Confira a resolução completa abaixo:

What is the correct way to complete the sentence below?

Today black spots or shadow zones around Somalia only benefit pirates. __________ (1) well-lit watchtowers, in the form of maritime security outposts, can help change that.