Question #N142
The discovery of the first planet orbiting a star outside our solar system, 51 Pegasi b, was announced in 1995. Astronomers using the radial velocity method, which relies on measuring the wobble of a star caused by the gravitational pull of an orbiting planet, confirmed the existence of 51 Pegasi b. Although astronomers have since found thousands of exoplanets, 51 Pegasi b remains a significant discovery because it ______ a new era in astronomy—the era of exoplanet discovery.
Which choice completes the text so that it conforms to the conventions of Standard English?
A. heralded
B. heralding
C. heralds
D. had heralded
Correct Answer is: A
The sentence is in the past tense, so a past tense verb is needed to maintain the correct tense. "Heralded" is the only past tense verb among the choices.