Questions (Erica-sama)

Are the words in BOLD letters natural?
Can you teach me words that can fill the brackets?

(1) Users will REPLACE their smartphones less frequently because more durable smartphones will be developed.
=Users will REPLACE their smartphones AT LESS INTERVAL because more durable smartphones will be developed.
=The (                       ) cycle of smartphones will be longer because ~ (same).

(2) I need to charge the battery every day because the LIFE OF THE BATTERY BETWEEN CHARGES is short.

(3)The wage gap between rank-and-file employees and company executives is becoming wider and wider.
=The wage gap between rank-and-file employees and company executives is becoming POLARIZED.

(4) The computer market will be SEPARATED (DIVIDED?): there will be a growing demand for low-and high-end computers, but MID-END computers will not be popular any more.

(5) Trial digital broadcast started last year. This year, FULL-SCALE digital broadcast will start.

(6) Laws related to driver monitoring system will be enacted this year, in addition to back cameras WHOSE LAWS were enacted last year.
(I would like to make this sentence shorter or simpler, too.)