The World War II made ______ impossible for Einstein to go on with his research.
It a Saturday afternoon in May ______ Margaret could arrange for me to meet her elder sister.
I failed in the examination last term and only then ____ the importance of studies.
________ he had won the first prize, he felt very happy.
It is not immediately clear __________ the housing price will go down.
---Did you sleep well here? ---_________. I was tired after the day’s work and was soon dead to the world.