[ Tenses ]
The extinction of certain species ____ scientists for years.
A. has worried
B. worries
C. is worrying
D. will worry
Select your answer:
Random Topics:
Uncountable NounsPresent Verb TensesGerunds and InfinitivesTenses & PassivePast Simple (to be)Speculation with Modal VerbsDemonstrative PronounModal Verbs and ConditionalsAdjective SuffixesClause Markers TOEFL GrammarOther quiz:
Grammar › ViewIdentify the part of speech of the underlined word.
The couch shows quality craftsmanship.
___
A. Noun
B. Pronoun
C. Verb
D. Adverb
E. Adjective
Gerunds and Tenses › View
. Which sentence correctly follows the rule that gerunds come after prepositions?
A. He is good at play the guitar.
B. He is good at playing the guitar.
C. He is good in playing the guitar.
D. He is good on playing the guitar.