[ Grammar ]
Listen! Someone _______ at the door.
A. knock
B. knocking
C. is knocking
D. knocks

Random Topics:
Verbals and GerundsGerund or to InfinitiveComparison & Modal Verbs in Passive VoiceContractions and ConjunctionsTo Infinitive or Gerund3rd Person SingularFuture Tense - will and going toAdjectives and ArticlesCOUNT - NONCOUNT NOUNSVerb IdentificationOther quiz:
Tenses › ViewThe stray cat ______ the milk hungrily.
A. drink
B. drunked
C. drank
Idioms › View
How can I take all these stains ___ from my tablecloth?
a. apart
b. away
c. out
Jim ___ a newspaper when the fire___.
A. was reading; was starting
B. read; started
C. was reading; started
D. were reading; started
Conjunctions › View
You can go to school by bus ____ walk.
A. or
B. and
C. but
