A group of astronomers _ meeting today.
The engineer and the astronomer _ meeting today.
One of the conference speakers _ an astronaut.
A few astronauts _ living at the Space Station.
Either Julie Payette or Jeff Williams _ American.
Julie Payette and Robert Thirsk _ Canadian.
Through the clouds, _ a glider.
Through the sky, _ the fighter jets.
The report on the planets _ on the desk.
All the reports on the mission _ on the desk.
Either the astronauts or the flight director _ at fault.
Either the flight director or the astronauts _ at fault.
One of the planets _ a year to complete an orbit.
Most of the stars _ billions of years to burn out.
The sun is one of the stars that _ light to the planets.
The stars, including the sun, _ light to the planets.
Someone from the astronomy club _ the telescope.
The astronomy club members _ the telescope on weekends.
Today the class _ the stars.
All students in that class _ the stars.
The news about the astronauts _ good.
Mars and Venus _ the closest planets to Earth.
Either Callisto or Callista _ Jupiter's moon.
Callisto and Ganymede _ Jupiter's moons.
A flag from every country _ painted on the rocket.
Flags from every country _ painted on the rocket.
Either Mars or Saturn _ a very thin atmosphere.
Both Jupiter and Saturn _ dense atmospheres.
A cluster of stars _ an interesting shape.
Stars, grouped together, _ an interesting shape.
One of the largest moon craters _ a huge area.
Groups of craters _ the moon's surface.
The Alpha star is one of the stars that _ the brightest.
The stars and planets _ brightly in the night sky.
Each of the students _ a computer.
All the students _ computers and telescopes.
Neither Venus nor Mercury _ life as we know it.
Which planets might _ some form of life?
One of the comets _ across the sky.
A star and a comet _ across the sky.
A family with five kids _ to Florida to see the launch.
The members of Jared's family _ to Cape Canaveral.
Io, one of the solar system's largest moons, _ Jupiter.
More than 16 moons _ Jupiter.
Everyone with binoculars _ craters on the moon.
Emily and Larissa _ a comet.
Everyone in the group _ when they see the meteor.
Several in the group _ when they see the meteor.
The public _ star parties at the local planetarium.
Members of the public _ special events at the museum.
Neither Cici nor Tim _ going to the star party.
Neither Rob nor his friends _ going to the star party.
Every one of the planets _ the sun.
All the planets in the solar system _ the sun.
Fifty percent of the class _ looked through binoculars.
Ten percent of the students _ looked through a telescope.
None of the group _ missing.
None of the students _ missing.
The light from the sun _ 8 minutes to reach Earth.
Light rays from the sun _ 8 minutes to reach Earth.
Every one of the other planets _ denser than Saturn.
All the planets _ denser than Saturn.
The book on galaxies and star clusters _ ready for pickup.
The books on our solar system _ ready for pickup.
Neither Juan nor Inge _ able to work the telescope.
Neither the students nor the teachers _ ready for the test.
Either Dave or Ella _ the star gazing at the observatory.
Either the members or the volunteers _ the observatory.
Your order for 3 solar filters _ ready for pickup.
The 3 solar filters in your order _ ready for pickup.
Through the star clusters and galaxies, _ the spaceship.
Through the space junk and debris, _ the spaceships.
Either the space station or the shuttle _ visible tonight.
Both the space station and the shuttle _ visible tonight.