Laser / device / concentrate / light waves / inten...

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

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

B. The laser is a device to concentrate light waves to an intense light beam. 

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

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