Помогите пожалуйста с английским! нужно поставить в вопросительную и отрицательную форму

1. Do students have vacation twice a year? Students don't have vacation twice a year.
2. Do the first year students study general engineering subjects? The first year students don't study general engineering subjects.
3.Will the dean send the students to a big plant in summer? The dean will not send the students to a big plant in summer.

1) What do students have twise a year?
2) What subjects do students study the first year?
3) When the dean will send the students to a big plant?

Отрицательная форма:
1) Students don't have vacation two twice a year.
2) First-year students don't study subjects of the general mechanical engineering.
3) The dean won't send students to big plant in the summer.

1 Do stdts have a vacation....или вопрос к подлежащему Who have vacations twice a year?
Stdts don't have....
2 по той же схеме
3 Will he send? Who will send? Where (или любое вопросительное слово) will he send?
The dean will not send....

в ответах предыдущих пользователей есть ошибки в порядке слов в вопросительных предложениях

1. twice a year students haven`t vacation
have studients vacation twice a year?

2. the first year studients don`t study general engineering subjects
do the first studients study general engineering subjects?

3. the dean will not send the studients to a big plant in summer
will dean send the studients to a big plant in summer