Mark the letter A, B, C or D to indicate the underlined part that needs correction in each of the following sentences. 1. You had better learning a foreign language before applying for a job. A B C 2. Annoyed by the receptionist's behaviour, they decided not staying in that hotel. A B C 3. Drug abuse have become one of America's most serious social problems. A B C 4. Every student in my class are good at English. A C D 5. The study of languages are very interesting. A B C D

Here's a breakdown of the errors in each sentence and the corrections:<br /><br />**1. You had better learning a foreign language before applying for a job.**<br /><br />* **Error:** The underlined part "learning" should be "learn". "Had better" is followed by the base form of the verb.<br /><br />* **Correction:** You had better **learn** a foreign language before applying for a job. (B)<br /><br /><br />**2. Annoyed by the receptionist's behaviour, they decided not staying in that hotel.**<br /><br />* **Error:** "staying" should be "to stay". After "decided," you need an infinitive ("to" + verb).<br /><br />* **Correction:** Annoyed by the receptionist's behaviour, they decided **not to stay** in that hotel. (C)<br /><br /><br />**3. Drug abuse have become one of America's most serious social problems.**<br /><br />* **Error:** "have" should be "has". The subject "Drug abuse" is singular.<br /><br />* **Correction:** Drug abuse **has** become one of America's most serious social problems. (B)<br /><br /><br />**4. Every student in my class are good at English.**<br /><br />* **Error:** "are" should be "is". "Every" indicates a singular subject.<br /><br />* **Correction:** Every student in my class **is** good at English. (C)<br /><br /><br />**5. The study of languages are very interesting.**<br /><br />* **Error:** "are" should be "is". The subject "The study" is singular.<br /><br />* **Correction:** The study of languages **is** very interesting. (C)<br />