2 11.4.1 11.4.2 Read the text and for questions 1-8 choose from the brain technologies (A-D).
Which brain technology
1 is a very small device?
2 will be able to work at a high speed?
3 allows research without experimenting
ing
on humans?
4 has already been in use for a number
of years?
5 will solve a problem users experience
with a current type of technology?
6 can aid scientists researching brain function?
7 could help people who cannot use
their limbs?
8 is known for helping someone speak?

2 и 6 будут Past indefinite 
Остальные ,соответственно,- Present Perfect
I have built a house.
I have built a house when he came out of school
I have never built houses
I haven't built a house
Have you ever built a tower?
We built a house today
I have not yet learned words
We haven't made tutorials
They have never seen a crocodile
They haven't seen yesterday the crocodile

Так. На заметку.
Время Present Perfect обозначает действие, которое завершилось к настоящему моменту или завершено в период настоящего времени

Время Past Simple(indefinite) используется для обозначения действия, которое произошло в определенное время в и время совершения которого уже истекло

1)The American school year isn't very long, It's about nine months, beginning early in September and continuing up to the first of June.UK - From the end of July to the beginning of September.
2)UK - There are three school terms in Britain.
3)UK - Six weeks. A - Three months.
4)The lessons are about an hour.
5)UK - In the summer from the end of July to the beginning of September. A - Three months for summer vacation.
6)UK - Holidays can vary from region to region. A -
Many vacations in the school year.
7)UK - The main subjects are English, Maths and Science. A - American children study four or five main subjects.
8)UK - Children get homework every day. A - At the end of each semester pupils get a report card from their teachers.