[单选题]RFID属于物联网的哪个层 ( )。
A.感知层
B.网络层
C.业务层
D.应用层

Scientists say they have achieved small-scale nuclear fusion in a tabletop experiment, using tried and true techniques that are expected to generate far less controversy than past such claims.
This latest experiment relied on a tiny crystal to generate a strong electric field. While the energy created was too small to harness cheap fusion power, the technique could have potential uses in medicine, spacecraft propulsion, the oil drilling industry and homeland security, said Seth Putterman, a physicist at the University of California at Los Angeles.
Putterman and his colleagues at UCLA, Brian Naranjo and Jim Gimzewski, report their results in Thursday’s issue of the journal Nature.
41. Held up to ridicule
Previous claims of tabletop fusion have been met with skepticism and even derision by physicists.
42. Sound theoretical basis
Fusion experts said the UCLA experiment will face far less skepticism because it confor