Fill in the blanks with an appropriate preposition.

Scientists have just discovered the biggest expanse (one billion light years across) ……………. (of / for / in) nothing. ……….. (Into / Inside / with in) the void, there are hardly any galaxies, planets, or black holes. ………….. (For / From / Since) a long time, astronomers thought that matter—which makes ………….. (out / up / off) everything in the universe—was distributed fairly evenly …………. (along / in / through) space, with only small empty spaces. The new find calls that assumption …………… (in / into / for) question.

The discovery began …………. (by / with / out) observations made …………… (with / by / for) other scientists about something called cosmic microwave background radiation, or CMB. The CMB is a glow of radiation that flooded outer space about 13.7 billion years ago, after the Big Bang. The CMB still fills the universe, but it has changed. …………… (Of / For / With) one thing, it has drastically cooled. Just after the Big Bang, the glow was billions of degrees hot. Now it is just 3 degrees ………….. (above / over / up) zero kelvin (K). That’s equal to -270 Celsius.

Answers

Scientists have just discovered the biggest expanse (one billion light years across) of nothing. Inside the void, there are hardly any galaxies, planets, or black holes. For a long time, astronomers thought that matter—which makes up everything in the universe—was distributed fairly evenly through space, with only small empty spaces. The new find calls that assumption into question.

The discovery began with observations made by other scientists about something called cosmic microwave background radiation, or CMB. The CMB is a glow of radiation that flooded outer space about 13.7 billion years ago, after the Big Bang. The CMB still fills the universe, but it has changed. For one thing, it has drastically cooled. Just after the Big Bang, the glow was billions of degrees hot. Now it is just 3 degrees above zero kelvin (K). That’s equal to -270 Celsius.