For ( ) , Lijnse et al. described concepts of radioactivity and radiation held by 15.- and 16.-year-old pupils in the Netherlands.
A.a instance B.an instance C.the instance D.instance正确答案D
For ( ) , Lijnse et al. described concepts of radioactivity and radiation held by 15.- and 16.-year-old pupils in the Netherlands.
A.a instance B.an instance C.the instance D.instance正确答案D