People have planted a great many trees in order to ________ wind and sand in the desert.
Whom do you expect to have ________ the baggage to the airport?
The airport is far from here, and ________ there on time, you'd better take a taxi.
The old couple walked rather slowly, and could be seen, from time to time, to stop and rest, ________ out to sea.
It was unbelievable that the fans waited outside the gym for three hours just________ a look at the sports stars.
The boy, ________ with his school work every day, felt rather tired and wanted to have a whole day to relax.