Writing prompt: The Advantages and Disadvantages of Private Cars

Student essay:
Private cars have some advantages.First,it makes travel easier.We can go to some close places in weekends.And with the development of technology, cars is becoming more and more comfortable to ride.It's very convenient for us.
But on the other side,cars also have some disadvantages.The most important one is air pollution.There are masses of hazardous substance in the automobile exhaust.Such as carbon monoxide,sulfur dioxide,solid particles and so on.They are not only bad for the environment ,but also for our health.
In my opinion,the advantages can't be replaced.And we should develop the energy technology fast.To keep the sky blue is our common aspiration.

Corrected essay:
Private cars have some advantages. First, they make travel easier. We can go to some nearby places on weekends. And with the development of technology, cars are becoming more and more comfortable to ride. It's very convenient for us.
But on the other side, cars also have some disadvantages. The most important one is air pollution. There are masses of hazardous substances in the automobile exhaust, such as carbon monoxide, sulfur dioxide, solid particles and so on. They are not only bad for the environment, but also for our health.
In my opinion, the advantages can't be replaced. And we should develop the energy technology fast. To keep the sky blue is our common aspiration.

Error analysis:
error_sentence: First,it makes travel easier.
correct_sentence: First, they make travel easier.
error: it makes
correction: they make
error_type: Pronoun Error
error_severity: 2
error_description: Pronoun Error: According to English grammar rules, the pronoun 『they』 should be used for plural nouns; in the original sentence, 『private cars』 is a plural noun, so the subsequent pronoun should be in the plural form 『they』 to maintain number agreement, therefore 〈it makes〉 needs to be changed to 『they make』 to conform to English grammar.

error_sentence: We can go to some close places in weekends.
correct_sentence: We can go to some nearby places on weekends.
error: close places in
correction: nearby places on
error_type: Adjective Error
error_severity: 4
error_description: ① Adjective Error: According to the context, the intention here is to express 'nearby'; 〈close〉 when referring to distance is mostly used for abstract concepts, while specific locations should use 『nearby』, therefore 〈close〉 needs to be changed to 『nearby』 to fit the context; ② Preposition Error: According to English expression habits, 『on』 should be used to indicate specific time ranges, therefore 〈in weekends〉 needs to be changed to 『on weekends』 to conform to expression habits.

error_sentence: And with the development of technology, cars is becoming more and more comfortable to ride.
correct_sentence: And with the development of technology, cars are becoming more and more comfortable to ride.
error: is
correction: are
error_type: Subject-Verb Agreement Error
error_severity: 3
error_description: Subject-Verb Agreement Error: According to English grammar rules, the original sentence has a subject-verb agreement error; the subject 〈cars〉 is plural, and the verb 〈is〉 in the original sentence is in the singular form, therefore the verb 〈is〉 needs to be changed to 『are』 to maintain subject-verb agreement.

error_sentence: There are masses of hazardous substance in the automobile exhaust.
correct_sentence: There are masses of hazardous substances in the automobile exhaust, such as carbon monoxide, sulfur dioxide, solid particles and so on.
error: substance
correction: substances
error_type: Noun Number Error
error_severity: 2
error_description: Noun Number Error: According to the context, 〈substance〉 in the original sentence should be in the plural form 『substances』 to indicate multiple hazardous substances, to fit the context.

error_sentence: There are masses of hazardous substance in the automobile exhaust. Such as carbon monoxide,sulfur dioxide,solid particles and so on.
correct_sentence: There are masses of hazardous substances in the automobile exhaust, such as carbon monoxide, sulfur dioxide, solid particles and so on.
error: .Such
correction: , such
error_type: Punctuation Error
error_severity: 2
error_description: Punctuation Error: According to English expression habits, having 〈Such as〉 directly followed by a main clause does not conform to standard expression; therefore, the original 〈. Such as〉 needs to be changed to 『, such as』 to connect to the main clause to conform to expression habits.