1 . We should __________ (集中于) our lessons and try not to be addicted to mobile phones. (根据汉语提示完成句子)

2 . 但是在网上花太多时间是不健康的，并且很难集中精力在生活中的其他事情上。
But __________ too much time online __________ and makes it __________ other things in life.

3 . Nowadays,more and more people around the world are________the Chinese culture and would like to pay a visit to this country.

A．responsible for

B．addicted to

C．attracted to

D．focus on