The danger of HINI was real, especially
题型:选择题
问题:
The danger of HINI was real, especially in the beginning,_____ little was known about the new disease.[ ]
A. if
B. because
C. when
D. before
The danger of HINI was real, especially in the beginning,_____ little was known about the new disease.[ ]
A. if
B. because
C. when
D. before