[ Grammar ]
Scientists ………. life on other planets yet.
A. didn’t discover
B. haven’t discovered
C. aren’t discovering
D. don’t discover

Random Topics:
Direct and Indirect SpeechCoordinating Conjunctions and Comparative AdjectivesAdjective SuffixesPassive Voice with Modal VerbsConditionals 1,2,3Asking and Giving OpinionGrammar - SimilesWish SentenceCausative VerbGerund - to InfinitiveOther quiz:
Mixed General Quiz › ViewLet there be ___ on Earth and let it begin with me.
a. peace
b. piece
Tenses › View
I’m sure they _________here soon.
A. are going to be
B. have been
C. will be
Prepositions of Place › ViewYour glasses are right _______ you….
A. in front of
B. on top of
Grammar › View
Mariam couldn’t buy lunch _______ she had lost her bag.
A. because
B. so
C. or
D. although
