B4

It's difficult to imagine life without shoes. Ever since people first started to make clothes, we have tried many different ways of protecting our feet.

(present perfect, т.к. с тех пор и по сей день)

TRY

B5

Early shoes  were made  out of leather.

(past simple passive, т.к. речь идет об определённом времени в прошлом; их сделали, а не они сами что-то делали)

MAKE

B6

In those days, people's shoes were much simpler than ours are today.

(наши)

WE

B7

They didn't have a heel and some shoes had very long toesto show how important the wearer was.

(past simple, т.к. речь идет об определённом событии в прошлом)

HAVE

B8

In colder countries, moccasins kept people's feet warm.

(past simple, т.к. речь идет об определённом событии в прошлом)

KEEP

B9

This was less important in warmer countries than in coldercountries, so open-toed sandals were more popular there.

(степень сравнения)

LITTLE

B10

Until 1790, you couldn’t fasten your shoelaces, because they hadn't been invented yet! It was in that year that an Englishman came up with the idea for the first time.

(прошедшее от can)

CANNOT

B11

Another thing we have today that people in the past didn’t wear different shoes for our left and right feet. They appeared in the middle of the 19^th century.

(past simple, т.к. речь идёт об определённом времени в прошлом)

NOT DO