I wonder when they ___ for Beijing. I will go to the train station to see them off when they ___.
You and I are lucky as we've ________ had to worry about finding clean water.
often
usually
never
________ English has a history of over 2,500 years,the first English dictionary didn't appear until the 17th century.
Because
Although
Unless
The minute the alarm clock ________,I got up and took a quick shower.
went by
went out
went off
Remember to use sunglasses to stop the sun from ________ directly in your eyes.
shine
shining
to shine
Everyone knows now that plastic pollution is ________ huge problem for the environment.
a
an
/