采用25×16血球计数板对某细菌进行细胞计数时,数得五个中方格的菌数为1000个,如菌液稀释倍数为100,则每毫升菌液含菌量()个/ml。
参考答案:
5×109
因为分数可以化成百分数,所以分数和百分数的意义是相同的.______.
St Pertersburg, ______is a very beautiful city, was once called Leningrad..
A.which
B.that
C.when
D.where