The couples went into the forest,but before long they became _________;they walked down different paths.

Why were so many people trapped intobuying the stock of the company—-______enough money within one night .

The book won’t until the end of the year.

Beijing’s first unmanned subway trains, which can run ______ without the control of any drivers, are expected to be put into operation next year.

When and where this took place _____ still unknown.