The Roman aqueducts were marvels of ancient engineering ______ they transported fresh water across many miles of difficult terrain.
Which choice completes the text so that it conforms to the conventions of Standard English?
- A
,
- B
(empty)
- Ccheck_circle
:
- D
, that
Explanation
A colon introduces an explanation of why the aqueducts were marvels. "," is a splice; " " is a run-on; ", that" creates a fragment.