Although everything seems to have been taken into consideration, ____ accident can happen when the astronauts walk in _____ space.
He wrote a letter ________ he explained what had happened in the accident.
Tom took a taxi to the airport, only _______ his plane high up in the sky.
—Have you heard about the recent election?—Sure, it _______ the only thing on the news over the last three days.
Don’t treat the vase as if it _______ made of steel.
Although we met with some difficulties in building the railway, we were still _____ about finishing it before the deadline.