19

By the second half of the 15' century Moscow became the undisputed centre of a unified Russian state. During the reign of the grand prince of Moscow Ivan III, the Kremlin was enlarged and it got brick walls more than a mile in length and in some places up to 60 feet (18 metres) high.
«the Kremlin was enlarged» – Кремль был увеличен (тогда) (Past Simple Passive)

ENLARGE

20

In 1534-38 the Kitay-gorod, previously protected only by earth banks and palisades, was also surrounded by a brick wall, with 12 towers.
«Kitay-gorod, previously protected only by earth banks» - Китай-город, ранее защищенный только земляными валами (Participle II - – пассивное причастие)

PROTECT

21

The town has grown and spread outside the walls to form what became known as the Bely Gorod (“White City”) in a semicircle around the Kremlin and Kitay-gorod.
«The town has grown and spread outside the walls» - Город вырос и распространился за пределы стен (уже вырос и продолжает расти) (Present Perfect – настоящее совершенное)

GROW

22

Most people probably know Albert Einstein as the most intelligent person who ever lived. His name has become part of many languages when we want to say someone is a genius, as in the phrase, “She’s a real Einstein”.
«His name has become part of many languages» - Его имя стало во многие языки. (уже стал и до сих пор это так) (Present Perfect – настоящее совершенное)

BECOME

23

In 1999, Time magazine named Einstein as the Person of the Century. No one could have guessed this would happen when he was at school. He was extremely interested in science but hated the system of learning by heart. He said it destroyed learning and creativity. He had already done many experiments, but failed the entrance exams to a technical college.
«No one could have guessed this would happen when he was at school. » - Никто не мог предположить, что это произойдет, когда он учился в школе. (скочек через время. Никто не мог предположить в прошлом, что произойдет в будущем) (Reported Speech – согласование времен)

HAPPEN

24

He didn’t let this setback stop him. He eventually graduated from university, in 1900, with a degree in physics. Twelve years later he was a university professor and in 1921, he won the Nobel Prize for Physics. He went on to publish over 300 scientific papers.
«he won the Nobel Prize for Physics.» – он выиграл нобелевскую премию по физике (тогда в прошлом выиграл) Речь идет о событии в прошлом. (Past Simple – простое прошедшее)

WIN