好氧法处理有机废水时,营养比C:N:P比例一般应为()。
A.20:5:1
B.100:20:1
C.100:5:1
D.50:2:1
参考答案:C
良性肿瘤的主要生长方式为
A.结节状生长
B.息肉状生长
C.膨胀性生长
D.蕈伞状生长
E.隆起状生长
—Mom, I'm tired of working in this company. I want _____ job.
—I don't agree with you. It's not easy to get a job like this.[ ]
A. one
B. a
C. an
D. another