We won’t give up ______ we should fail twenty times.

The science of medicine, _______ progress has been very rapid lately, is perhaps the most important of all the sciences.

When choosing furniture, you focus on function while I think more about the design.—That’s_____we differ

It is_____the pupils do in their spare time_____ really______ them to take their place in society as citizens when they grow up.

I’m sorry I didn’t recognize your voice just now. It sounded quite different ______ the phone.