Here are suggestions to fill in the blanks:

(23) **interesting findings**
(24) **their**
(25) **leisure activities**

The completed passage would read:

"A recent survey conducted by TIRA, a Vietnamese research company, highlights (23) **interesting findings** about the lifestyles of Vietnamese teenagers in urban areas. There is an imbalance in their consumption of time for studying and recreational activities. On average, these teenagers spend 9.5 hours a day (24) **their** studies at school and at home. They only have about four hours for (25) **leisure activities**. Most of this time is spent on watching television and the internet, where they chat through social networks..."