Упражнение 5. Используйте наиболее подходящую форму глагола в скобках; если возможны оба варианта, объясните разницу в их употреблении

Пример: Before I960, astronomers (have not spotted, had not spotted) had not spotted stars that send out both light and sound waves.

In 1960, two astronomers at Mount Palomar Observatory (had discovered, discovered) a starlike object at the edge of the universe. The astronomers were astounded to discover that this object (emits, was emitting) as much light as a thousand galaxies. Today, we (use, are using) the name quasar, which (stands, stood) for quasi-stellar. Quasi-stellar (meant, means) “starlike object.” So far, more than three hundred quasars (had been found, have been found) in space. Although astronomers today generally (had agreed, agree) that quasars arе powerful, fast-moving energy sources, they (will contradict, contradict) each other’s theories about the origin of quasars. One group currently (has been believing, believes) that quasars (consisted, consist) of giant, swirling masses of gas. These astronomers (say, said) that the gas (collapsed, is collapsing) on itself all the time, which is why quasars (had generated, are generating) so much energy. Other scientists (were asserting, assert) that quasars (develop, have been developing) from explosions of matter and antimatter, just as science fiction writers (predict, have been predicting) for many years. When scientists (had conducted, conduct) experiments that (brought, bring) matter and antimatter together, an explosion (will occur, occurs). Until we (understand, understood) more about the birth and death of galaxies, we probably (will not discover, have not discovered) the real story behind quasars.

1.1.5 Согласование времен

Согласование времен (sequence of tenses) используется, если сказуемое главного предложения стоит в прошедшем времени (past simple). В этом случае сказуемое придаточного предложения согласуется во времени со сказуемым главного предложения, т. е. вместо настоящего времени (present) используется прошедшее (past), а вместо будущего времени – так называемое “будущее в прошедшем” (future in the past). Речь идет о будущем, о котором говорилось в прошлом. В русском языке подобного согласования времен нет, поэтому при переводе надо помнить, что если глагол в главном предложении стоит в прошедшем времени (past simple), то глагол придаточного предложения следует переводить настоящим временем (вместо прошедшего), или будущим временем:

She said that she was a librarian.	Она сказала, что она библиотекарь (а не – была библиотекарем).
We knew that the plant would be put into operation soon.	Мы знали, что завод будет скоро введен в эксплуатацию.

В неформальном современном английском языке согласование времен часто не соблюдается, например:

The article said that the new theory is very promising.

В статье говорилось, что новая теория является многообещающей.

Упражнение 6. Глаголы в следующих предложениях стоят в правильном порядке. Измените основной глагол предложения как указано в скобках. Затем сделайте необходимые изменения для согласования времен. Некоторые предложения могут иметь несколько правильных вариантов

Пример: Swimmers who prepare to swim the 21.4-mile English Channel that separates England from France face a difficult challenge. (Change prepare to prepared.)

Swimmers who prepared to swim the 21.4-mile English Channel that separates England from France faced a difficult challenge.

The swimmers depart from either shore and arrive on a French beach or at the English cliffs equipped with only noninsulated swimsuits, bathing caps, goggles, noseclips, earplugs, grease, and light sticks for night swimming. (Change depart to departed.) They prepare for the swim by greasing themselves with lanolin and special oils, which make them glide more easily through the cold water. (Change prepare to had prepared.) Throughout the journey, the swimmers faced obstacles like sewage and oil slicks that sometimes made their tongues and throats swell and caused breathing problems. (Change faced to face.) Confronting water temperatures as low as 55 degrees Fahrenheit also threatened the swimmers, and many of them fell victim to hypothermia, a below-normal body temperature that can cause death. (Change threatened to threatens.) Often, after a few miles, even the best swimmers had blue lips and shivering bodies, and they became confused. (Change had to will have.)