The old couple are now quite ______ as their son is out of danger.
What shall we use for power when all the oil in the world has _______?
How can he _______ without money for food during the journey?
John said he had been working in the office for an hour, _______ was true.
The science of medicine _______ progress has been rapid lately is perhaps the most important of all the science.
Is this the reason _______ at the meeting for his carelessness in his work?