Fill in the gaps:

This sentence requires correction based on the principle of subject-verb agreement.

The main subject of the sentence is "The basket," which is a singular noun. The phrase "containing ten apples" is a participial phrase acting as an adjective, modifying "basket." It does not alter the number (singularity or plurality) of the main subject.

Since the subject "basket" is singular, the verb must also be singular. The original sentence used "were," which is a plural verb. It should be replaced with the singular past tense verb "was" to agree with the singular subject.

None of us are perfect. = None of us is perfect.

The original sentence contains a common grammatical error related to the use of 'less' and 'fewer'.

    
• Fewer: Used for countable nouns (items that can be counted individually), such as 'people', 'books', 'cars', 'students'.
    
• Less: Used for uncountable nouns (mass nouns or abstract concepts that cannot be counted individually), such as 'water', 'time', 'money', 'information', 'sand'. It can also be used for singular countable nouns when referring to quantity or degree rather than individual units (e.g., "less than a mile").

In the given sentence, 'people' is a countable plural noun. Therefore, the correct comparative adjective to indicate a smaller quantity is 'fewer'. The phrase 'no fewer than' correctly implies that the number of people was at least one thousand, emphasizing the large quantity of countable items.