It could take 4-6 months before the firs
题型:选择题
问题:
It could take 4-6 months before the first batch(批)of vaccines (疫苗)are available to fight A/H1N1 flu ________ as swine flu, WHO officials said.
A.known
B.to know
C.knowing
D.having known
It could take 4-6 months before the first batch(批)of vaccines (疫苗)are available to fight A/H1N1 flu ________ as swine flu, WHO officials said.
A.known
B.to know
C.knowing
D.having known