Question

—Fire is very useful to human!
—Yes, especially in winter a fire _____________warm.

A．used to keep	B．can be used to keep
C．is used to keeping	D．was used to keeping

Answer 1

B

考查固定用法。used to do，過去常常，現在已不再如此；be used to do sth.被用于做某事；be used to doing sth.習慣于做某事。根據句意，應是火被用來取暖。所以選B。