1.The students were excited about these activities

2.we can use a smartphone for getting access to the internet and send message.

excited about: bị kích thích làm việc gì

use sth for V_ing : dùng cái gì để làm gì

The students found these activities exciting 
-the students were excited about these activities.

S + find + something/doing something + adj.

→S + be + adj + giới từ + something/doing something.

2 we can use a smartphone to get access to the internet and send messages (for)

→A smart phone can be used for getting access to the Internet and send massages.

S + can use + O.

→S(O) + can be used + for + V_ing.