Great efforts to increase grain production if food shortages are to be avoided.

The initial tunnels were just ___________ the surface of the ground. People were transported in carriages, which were ___________ the narrow tunnels by steam engines.

So you missed the important meeting yesterday–_________. I got there five minutes before it wasfinished.

He bought glee him muchknowledge and ______ could help him to kill the time．

David said that it was because of his strong interest in literature___hechose the course.