A-A+
One implication in this passage is that ______
问题详情
One implication in this passage is that ______.
A．all RDAs have been established
B．not all RDAs have been established yet
C．it"s not important to know RDAs
D．RDAs are necessary only for sick people
参考答案
正确答案：B
解析：推断题型。见文章第二句：These are known as the Recommended Dietary Allowances(RDAs)and are updated regularly based on new research in nutrition．可知RDAs要经常更新，所以选项A不对，选项C、D也披排除：只有选项B正确。
