_____, we decided to spend the night at the foot of the mountain.

____ and we’ll get everything ready for the taking off.

      surprises most of us.

It is worth pointing out that the mishearing or misunderstanding of instructions in English, and the use of another language, in an international conversation, ______ two recent aircraft accidents.

I made a promise to myself______ this year, my first year in high school, would be different.

Evdence has been found through years of study         children’s early sleeping problem are likely to continue when they grow up.

I walked up to the top of the hill with my friends, ______ we enjoyed a splendid view of the lake.

—How about camping this weekend, just for a change?
—OK, ______ you want.

As long as the laws of nature ______, there will be tornadoes.

Some scientists have questioned the theory ______ CO₂ is causing dangerous global warming.