D
n.加倍；折回；衬里；防护板
n.加倍；折回；衬里；防护板
英英释义
"doubling with a computer took no time at all"
"I decided his double was a bluff"
经典引文
The rapid doubling of the population.
出自：R. W. EmersonIntourist had given some of our booked rooms to a delegation from Mongolia, which meant a lot of doubling up.
出自：A. GarveA violinist anxious to learn a 'doubling instrument'.
出自：Melody Maker