Read the passage and choose the correct answer (A, B, C or D).
Earth, our beautiful home planet, is the only astronomical object to accommodate life (23) . . . . . we know it. Scientists believe Earth was (24) . . . . . approximately 4.5 billion years ago. It is the fifth-largest (25) . . . . . in our solar system. Its equatorial diameter is about 12,074 kilometres. Earth is the third-closest planet to the sun. The distance from Earth to the sun is roughly 149,600,000 kilometres. It (26) . . . . 365,3 days for Earth to obit the sun, and 24 hours to rotate on its axis. The surface temperature ranges from -88 to 58° C. Nearly 70 percent of Earth’s surface is covered by ocean, (27) . . . . has an average depth of about 4 kilometres. In 2015 it was estimated that 7,3 billion humans are living on Earth.
Quesstion 23:
A. as
B. so
C. because
D. that