[ Present Perfect Continuous Tense ]
The Scientist mixes the formula
A. The Scientist has been mixing the formula
B. The Scientist has been mixxing the formula

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Tenses and StructureGrammar - QuantiflierPast simple vs Present perfectWas and WereMaritime Vocabulary and GrammarVerb AbilityPast Perfect TenseFuture TensesModals and Active and Passive VoiceLinking Words & PhrasesOther quiz:
Grammar › ViewHow many fish are there in the sea? ______
A: There are much fish in the sea.
B: There are many fishes in the sea.
C: Are there millions of fish in the sea.
D: There are millions and millions.
E: Are millions and millions of fish in the sea.
Grammar › View
Don’t worry. You __________________anything to help.
A. wouldn’t have done
B. could have done
C. couldn’t have done
D. couldn’t did
E. shouldn’t have done
Vocabulary and Grammar › View. My wife’s mother is my _______.
A. aunt
B. mother-in-law
C. sister
D. mother
Personal Pronouns › View
… are watching TV. (my mother and I)
A. Them
B. We
C. They
D. You