1. My brother works an engineer.
(?) Does my brother work...?
(-)My brother doesn't work...
2. Our parents live in the country.
(?) Do our parents live...?
(-) Our parents don't live...
3. They work at a plant.
(?) Do they work...?
(-) They don't work...
4. My parents buy fruit in this supermarket.
(?) Do my parents buy...?
(-) My parents don't buy...
5. He often goes on business.
(?) Does he often go...?
(-) He doesn't often go...
Объяснение:
Вообще-то в (present simple) настоящем простом предложении, главное сказуемое для 3-го лица единственного числа берет окончание -s/-es.например: My brother works an engineer. Our parents live in the country.B вопросе вс глагол do/ does переходит в начало предложения, всегда dоеs используется для 3-го лица, единственного числа, с такими как he/she/it. в вопросе главное сказуемое не берет окончаний -s/-es для 3-го лица единственного числа. например: does my brother work as an engineer? do our parents live in the country?Отрицание образуется с NOT после do/does например: my brother does not work as an engineer. our parents do not live in the country.