[ Adverb and Noun Clauses ]
When ………………. is not known.
A. was the wheel invented
B. the invention of the wheel
C. inventing the wheel
D. the wheel was invented
Select your answer:
Random Topics:
Past Simple, Past Continuous, Past Perfect, Past Perfect ContinuousNumbersNouns - Word Form-IONSimple Past TenseGrammar: Simple Past and Past ContinuousEssential and Nonessential ClausesPast Simple vs Present SimpleCountable QuantifiersGrammar - Present PerfectOther quiz:
Adjective Clause › ViewYesterday, I was introduced to the woman …….. in front of my house.
A. That live
B. Who have lived
C. Lives
D. Who lived
E. She lives
Mixed General Quiz › View
She hasn’t been home ——- her marriage.
A. When
B. Unless
C. Since
D. While