C. Choose the FALSE sentence. 1) Mrs. Thompson taught Maths. 2) Mrs. Thompson could see the difference between the boys. 3) Mrs. Thompson had been the boys' teacher for a long time.

Краткое пояснение:

Пошаговое решение:

1. Утверждение 1: Mrs. Thompson taught Maths. В тексте сказано: «However, things became funnier when their Maths teacher, Mrs. Thompson, came in.» Это утверждение истинно.
2. Утверждение 2: Mrs. Thompson could see the difference between the boys. В тексте сказано: «Although she had taught them for years, she was bad at recognizing the boys' faces.» Это означает, что она не могла их различить, следовательно, это утверждение ложно.
3. Утверждение 3: Mrs. Thompson had been the boys' teacher for a long time. В тексте сказано: «Although she had taught them for years...» Это означает, что она была их учителем долгое время, и это утверждение истинно.

Ответ: 2