[ Vocabulary ]
What is a fossil known to have lived in a particular geologic age that can be used to date the rock layer in which it is found?
A. hypothesis
B. index fossil
C. jellyfish fossil
D. hippopotamus fossil

Random Topics:
Gerund/ To Verb/ VerbQuantifiers / Prepositions of Time and Comparative AdjectivesGerunds and InfinitivesInterrogative Pronouns & AdverbsThere is, There are, Some, AnyPersonal Pronouns and VerbFuture FormsRelative PronounsComparative AdverbsIndefinite and Definite ArticlesOther quiz:
Grammar › ViewShe spent hours __________ herself in her studies.
A. immersing
B. submerging
C. drowning
D. floating
Grammar › View
She ___ her homework every day after school.
A. do
B. does
C. doing
D. did
Modals and Advice › ViewMight they have already left for the airport?
A. Maybe
B. No
C. I don’t know
D. Yes
Time Clauses of Future › View
Don’t worry. I’ll call you ______ I open the letter with my exam results.
A. as soon as
B. if
C. unless
