—What’s all that noise about outside?—Oh, I forgot to tell you. The road to the railway station ______.
In the 1950s in the USA, most families had just one phone at home, and wireless phones _______ yet.
haven't invented
haven't been invented
hadn't invented
hadn't been invented
If you don't understand something, you may research, study, and talk to other people _______ you figure it out.
because
though
until
since
Many airlines now allow passengers to print their boarding passes online ______ their valuable time.
save
saving
to save
saved
Jane moved aimlessly down the tree-lined street, not knowing ______she was heading.
why
where
how
when
______ birds use their feathers for flight, some of their feathers are for other purposes.
Once
If
Although
Because