Why does the river smell terrible? —- Because large quantities of water______

Mike, I’ll go for the football match. — ________I hope you win the game.

I hope you don’t mind my opening thewindow.— _____ . It’s much too hot here.

The construction of the two new railway lines ________ by now.[ ]

We havehurried all the way to the airport – the flight was called off because of thefoggy weather．