—Where did you see your friend?—It was in the super market ____ I was doing shopping.
Dad had to cycle to work this morning because his car _______ at the garage.
John passed the examination though he had only spent _______ on the subject as others had done.
He started to work dilligently _____ he came up with the idea of hybrid rice for the first time in the 1960’s.
Once e-mail learners _______ with the basic knowledge of how to use the network, they ______ to a local network and a global network.
Yuan Longping, known as the “father of hybrid rice”, doesn’t care about money or about ____ people call position.