37. Which of the following can best replace the word “launched” in line 2? (A) Experienced. (B) Introduced. (C) Attended. (D) Organized.

39. According to the passage, which of the following feature is NOT mentioned regarding the app “Recommendation”? (A) Users can use it to ask questions. (B) It allows users to give comments on posts. (C) It is a unique tool for taking photos indoors. (D) Users have to turn it on when they need to use it.