The Solar System has been a com-plicated wonder for the astronomers. This is a (236) to which we may never have the exact answer. Man has wondered (237) the age of the Earth (238) ancient times. There were all kinds of (239) that seemed to have the (240). Butman could notbeginto (241) about the question scientifically until about 400 years (242). when it was proved that the (243) revolved round the Sun and the Earth was a (244) of our Solar System, then scientists knew where to (245)

Options

A. since
B. during
C. around
D. from

Answer

A

Explanation

since (Prep.)