Fill in the blanks in the sentence below with suitable articles. Choose your answer from the given options.
Large tremors can cause perturbations in _______ Earth’s gravitational field - and as these signals travel at _______ speed of light, they open up _______ possibility of much more rapid detection of quake magnitude.
1
an; the; the
2
the; the; the
3
the; a; the
4
the; the; a