黑素细胞占基底层细胞的比例约为()。
A.30%
B.40%
C.50%
D.90%
E.10%
参考答案:E
—We________gas.I'm afraid we can't go much further.
—I know there's a gas station ahead.Sure it will last us until we get there.
A.are running out
B.have run out
C.are running out of
D.have run out of
一般“产品开发能力强”常用于描述()。
A.工业企业
B.商业企业
C.服务业
D.金融业