His latest research is at the   of genetic science. 
#5898
A
maiden voyage
B
cutting edge
C
focus group
D
daily basis
推荐题目
He had no special ______ and was treated just like every other prisoner.
#5349
A
privileges  
B
possessions 
C
identifications
D
treasures
Mr. Li has ordered ___ for the school lab.
#7371
A
three equipments
B
three pieces of equipments
C
three pieces of equipment
D
three pieces equipment