Easy for noobs choose one that will sound right:
(with this objective) or (too) or (however) or (thus) or (frequently)

However.

Explanation:

The first sentence provides good effects. But, the sentences after it provides some of the negative effects of electronics. Because of the change of thought, you would use a word that shows the difference between the sentences. "However," is a good transition that changes the what the reader views.

hello : o)

b. les encantan los juguetes nuevos

hope this ! : o)