There are still many problemsbefore we are ready for a long stay on the Moon.
Better _______ the local customs or you will have a hard time.
I wondered what great difficulty he had ________ the plan.
It was the third time that I ________ of the changes of the timetable.
He is driving a truck _______ of bananas when he came off the road at the bend and fell three hundred metres down the mountain.
__________ the heavy fog, our flight was held up eventually.