B4

If you ever have had an X-ray as part of a medical checkup, you owe thanks to Wilhelm Roentgen.
(present perfectт.к. говорится о периоде, который начинается в прошлом и длится до настоящего)

HAVE

B5

Medical X-rays have been one of the most powerful, useful and life-saving diagnostic tools ever developed.
(present perfectт.к. он был и есть)

 BE

B6

In 1895 Wilhelm Roentgen was an academic professor at the University of Wurzburg, Germany, doing research into the effects of passing electricity through gas-field bottles.
(past simpleт.к. говорится о конкретном времени в прошлом)

BE

B7

In November of that year he began experiments in his home basement lab.
(past simpleт.к. говорится об определённом времени в прошлом)

BEGIN

B8

On November 8, he noticed that a photographic plate that had been wrapped in black paper and tucked inside a leather case in the bottom drawer of his desk had mysteriously been imprinted with the image of a key.
(past perfect т.к. он заметил что-то, что случилось до того момента, когда он это заметил)

WRAP

B9

The only key in the room was an oversized key for a garden gate he had tossed into the desk's center drawer over a year ago.
(1.past simpleт.к. говорится о конкретном событии в прошлом. 2. Past perfectт.к. это “предпрошедшее” время. Он бросил ключ в ящик, до определённого события в прошлом)

BE

 TOSS

B10

The image on his photographic plate was of that key.
(past simpleт.к. говорится о конкретном времени в прошлом)

BE

B11

Two weeks later he was able to prove the existence of these mysterious rays, which he named "X-rays" and after it "X" was used to represent the unknown.
(1.past simpleт.к. говорится о конкретном времени в прошлом,
2.past simple passiveт.к. это определённое событие в прошлом)

NAME

 USE

B12

By this time, he had seen that X-rays could pass through wood, paper, card board, cement, cloth, etc.
(past perfectт.к. действие завершилось к определённому моменту в прошлом)

SEE

B13

Roentgen, however, began six weeks of intensive study before releasing his results on the nature and potential of X-rays.
(past simpleт.к. говорится о конкретном времени в прошлом)

BEGIN

B14

Within a month Wilhelm Roentgen's X-rays were the talk of the world.
(past simple т.к. говорится о конкретном событии в прошлом)

BE

B15

Thus X-rays were developed as the first noninvasive technique which allowed doctors to see inside the body.
(past simple passiveт.к. это определённое событие в прошлом)

DEVELOP

B16

X-rays led to the more modern MRI and CT technologies.
(past simple т.к. говорится об определённом событии в прошлом)

LEAD

B17

The discovery of X-rays earned Roentgen the 1901 Nobel Prize in physics.
(past simpleт.к. говорится об определённом событии в прошлом)

EARN