abhi1693 wrote:
I think D is the right answer.
'have succeeded' is the verb used for main action
As a general rule, all the direct consequences or supporting clauses have -ing modifiers in them.
Quote:
Scientists at the Los Alamos National Laboratory have succeeded for the first time in mining heat from the Earth’s interior to produce energy on a commercial scale, enough for generating electricity efficiently and for heating factories and homes.
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