YDS GRAMMAR REVISION TEST 1 45. Soru

Bu Testin Birincisi missbeliever

100 %

45.

- The rocket engine ....... in the 1920s, but it ....... extensively until World War II.

had been invented/hasn't used

has been invented/hadn't been used

was inventing/wasn't being used

had been inventing/wouldn't have used

was invented/wasn't used