After . . . . . . . . fourth lesson, English students have . . . . . . . . break of . . . . . . . . hour and . . . . . . . . half for dinner. A. a, a, a, a B. the, a, no article, a C. a, the, an, a D. the, a, an, a

The correct answer is: After the fourth lesson, English students have a break of an hour and a half for dinner.

The article “the” is used before a noun that is specific or unique. In this case, the fourth lesson is specific because it is the fourth lesson in a series of lessons. The article “a” is used before a noun that is general or non-specific. In this case, the break is general because it is any break, not a specific break. The article “an” is used before a noun that begins with a vowel sound. In this case, the hour is not preceded by an article because it does not begin with a vowel sound. The article “a” is used before a noun that begins with a consonant sound. In this case, the half is preceded by an article because it begins with a consonant sound.

Here is a more detailed explanation of each option:

• Option A: After a, a, a, a. This option is incorrect because the article “a” is used before a noun that is general or non-specific. In this case, the break is general because it is any break, not a specific break.
• Option B: The, a, no article, a. This option is incorrect because the article “the” is used before a noun that is specific or unique. In this case, the fourth lesson is specific because it is the fourth lesson in a series of lessons. The article “a” is not used before a noun that is specific or unique.
• Option C: A, the, an, a. This option is incorrect because the article “a” is used before a noun that is general or non-specific. In this case, the break is general because it is any break, not a specific break. The article “the” is used before a noun that is specific or unique. The article “an” is used before a noun that begins with a vowel sound. In this case, the hour is not preceded by an article because it does not begin with a vowel sound.
• Option D: The, a, an, a. This option is the correct answer because the article “the” is used before a noun that is specific or unique. In this case, the fourth lesson is specific because it is the fourth lesson in a series of lessons. The article “a” is used before a noun that is general or non-specific. In this case, the break is general because it is any break, not a specific break. The article “an” is used before a noun that begins with a vowel sound. In this case, the hour is not preceded by an article because it does not begin with a vowel sound.