微量元素是指()
A.人体含量很少的元素
B.食物中含量很少的元素
C.自然界含量很少的元素
D.人体吸收率很低的元素
E.人体利用率很低的元素
参考答案:A
重症胰腺炎化验检查可出现()。
A.CA199显著升高
B.血浆VIP(血管活性肠肽)水平升高
C.CT可见胰腺占位性改变
D.抗中性粒细胞胞质抗体阳性
E.低钙血症
—Betty suggested going to the park instead of shopping this Saturday.
—That's right, because most shops in this town are _____ on weekends. [ ]
A. close
B. closed
C. open
D. opened