B. Each of the following sentences contains ONE mistake. Find it out and correct it. 1. 1. Henry mustn’t be at home because he phoned me from the farm just now. 2. Jack is a bilingual person. He may speak English and Japanese. 3. Mary can know the answer to the question. I’m not sure. 4. You mayn’t tell anyone about this — it’s a secret. 5. Mother is out, so I must look after the shop.