Laser/ device/ concentrate/ light waves/ intense/...

Câu hỏi: Laser/ device/ concentrate/ light waves/ intense/ beam.

A. Laser is a device concentrating light waves into an intense light beam.

B. The laser is a device concentrating light waves on an intense light beam.

C. The laser is a device which concentrates light waves into an intense light beam.

D. Laser is a device which concentrates light waves to an intense light beam.