______to the sun for too long can hurt your skin.
Scientists have discovered amazing evidence showing how the human body rebuilds _______ while we sleep.
—Why didn’t you remind him of the possible danger?—But what _______ otherwise? He never listens to me.
The new means of transport ________ in this city, so whether it will work out remains to be seen.
It wasn’t until then _______ their marriage was breaking up because they had little in common.
The earthquake in Japan, measuring 9.0 on the Richter Scale, was so violent _______ cause a series of explosions of the nuclear reactors in several power stations.