Question:
Find the mistake: Scientists think there is water on Mars a long time ago.
-
A.
a -
B.
on -
C.
is -
D.
think
Reference explanation:
Correct Answer:
Knowledge: Simple past tense
Explain:
Recognizing signs: “a long time ago” – a long time ago => simple past tense
Simple past tense: S + V_ed
Describe an action that happened in the past
Edit: is => was
Scientists think that there was water on Mars a long time ago.
Choose C.
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