______ is often the case is that Tom doesn’t study hard and fails in passing an exam.

_____ we have enough evidence, we can’t win the case.

Although the old man is in his sixties, ___ he walks fairly fast.

So although Fleming discovered penicillin, it was over a decade ___________someone else turned penicillin into the great drug of the 20th century.

Mark needs to learn Chinese ______ his company is opening a branch in Beijing.