Present Perfect and Past

Present and Past

Тесты на времена и залоги

The microwave background radiation

In 1949, two of Gamow’s students, Ralph Alpher and Robert Herman, (1) ____ (calculate) that the temperature of the microwave background radiation today (2) ___ (be) about 5K. Remarkably, this prediction (3) ____ (ignore) by observational astronomers for the next 15 years! The microwave background radiation (4) ____ finally ___ (discover) accidentally in 1964 by Arno Penzias and Robert Wilson while they (5) ____ (measure) noise inherent in radio receivers. They (6) ____ (make) an extremely sensitive radio receiver, but wherever they (7) ___ (look) in the sky, they (8) ____ (find) that it was a little hotter than they (9) ___ (expect). It turned out that they (10) ____ (discover) the microwave background radiation.

Since this discovery there (11) ____ (be) many observations of this radiation to try to detect variations in temperature along different lines of sight. One of the remarkable facts of astrophysics to emerge over the last more than 30 years (12) ___ (be) the extraordinary smoothness of this fossil radiation. We now (13) ____ (know) that the temperature of the radiation (14) ____ (vary) by less than one part in 30,000 on an angular scales, once one (15) ___ (make) the correction for the Doppler effect. The amazing smoothness of the microwave background radiation (16) ___ (tell) us that the universe is “simple” in the sense that it is both homogeneous and isotropic. In other words, if we (17) ___ (look) at the content of a small volume of the universe and (18) ____ (compare) it to any other such volume, the average properties (19) ____ (be) the same.

Упр.5.13.1. Выберите вариант ответа, который вы считаете правильным.

a. _________________ this week? "No, she's on holiday."

A Is Susan working B Does Susan work C Does work Susan

b. I don’t understand this sentence. What __________?

A does mean this word B does this word mean C means this word

c. John __________________ tennis once or twice a week.

A is playing usually B is usually playing C usually plays D plays usually

d. How _________________ now? Better than before?

A you are feeling B do you feel C are you feeling

e. It was a boring weekend. _______________________ anything.

A I didn't B I don't do C I didn't do

f. Tom _________________ his hand when he was cooking the dinner.

A burnt B was burning C has burnt

a. Jim is away on holiday. He __________________ to Spain.

A is gone B has gone C has been

b. Everything is going well. We _________________ any problems so far.

A didn't have B don't have C haven't had

c. Linda has lost her passport again. It's the second time this ________________.

A has happened B happens C happened

d. You're out of breath. ___________________________?

A Are you running B Have you run C Have you been running

e. Where's the book I gave you? What _____________________ with it?

A have you done B have you been doing C are you doing

f. We're good friends. We __________________ each other for a long time.

A know B have known C have been knowing D knew

g. Sally has been working here ___________________.

A for six months B since six months C six months ago

h. It's two years ____________________ Joe.

A that I don't see B that I haven't seen C since I didn't see D since I saw

i. They _________________ out after lunch and they've just come back.

A went B have gone C are gone

j. The Chinese __________________ printing.

A invented B have invented C had invented

k. Ian ____________________ in Scotland for ten years. Now he lives in London.

A lived B has lived C has been living

l. The man sitting next to me on the plane was nervous because he ________ before.

A hasn't flown B didn't fly C hadn't flown D wasn't flying

m. ____________________ a car when they were living n London?

A Had they B Did they have C Were they having D Have they had

n. I ________________ television a lot but I don't any more.

A was watching B was used to watch C used to watch

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