典型矽结节主要表现为()。
A.肺泡巨噬细胞大量聚集
B.尘细胞的大量堆积
C.成纤维细胞的大量增生
D.嗜酸性白细胞的大量存在
E.胶原纤维与各种细胞
参考答案:C
It is estimated that considerable amounts of money______needed for the construction of the
underground. [ ]
A. has been
B. were
C. are
D. is being needed
函数f(x)=2cos2x+sin2x的最小值是().