[ Grammar ]
Other radioactive elements ______ since: actinium (Debierne), radiothorium and mesothorium (Hahn), ionium (Boltwood), etc.
A. were discovered
B. are discovered
C. have been discovered
D. had been discovered
Select your answer:
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Grammar › ViewIdentify the verb in this sentence:
Sarah voted for the very first time!
A. voted
B. Sarah
C. first
D. very
World Literature Vocabulary › View
The hurricane intensified as it was traveling to the West Coast. Intensified means:
A. became strong
B. became stronger
C. became weak
D. became a joke