46. This girl is not old enough to drive a car. (Uses "enough" to indicate insufficient age)

47. The last time they met was when they left school. (Uses "was" to show the point in time)

**48. The information I got from the assistant was so confusing that I didn't know what to do. (Uses "such" to emphasize the high degree of confusion)
ORThe assistant's information was so confusing that I didn't know what to do. (Focuses on the assistant's role)

49. The house by the river hasn't been sold yet. (Uses "been" with the past participle "sold" to indicate an ongoing state)

50. Everyone arrived at the party early, right? (Uses "were" to maintain the question form and imply agreement)