[ Grammar ]
John doesn’t know how_________the computer on.
A. to switch
B. switching
C. to switching
D. to have switched

Random Topics:
Tenses, Determiners & Subject Verb AgreementGrammar- Later/LatterModal "Have to"There is or There areComplex PrepositionsModals and PhrasesPresent Continuos TensePresent tense AffirmativePresent Tenses and VocabularyPast Continuous Tense & Past ModalsOther quiz:
Present Simple & Present Continuous › ViewThey ………………. swimming. They …………….. sunbathing.
A. aren`t ; are
B. don`t ; are
Verb Patterns › View
promise
A. to work
B. working
Grammar › ViewThere are always regional __________ in every country.
A. differs
B. different
C. differences
Modals › View
You ___________ send text messages when you are driving.
A. haven’t
B. hasn’t
C. should
D. mustn’t