题目选项分析

Statisticians studying the health effects of uranium mining on Navajo communities have found others besides miners and millworkers to be affected; birth defects, altered male and female ratios at birth, and cancer among children occur much morein mining than in non-mining communities.

Statisticians studying the health effects of uranium mining on Navajo communities have found others besides miners and millworkers to be affected; birth defects, cancer among children, and altered birth ratios of males and females occur much more frequentlyin mining than in non-mining communities.