下载APP
参考答案：
参考解析：
刷刷题刷刷变学霸
举一反三
【单选题】If those "mad moments"— when you can’t recall what your friend has told you or where you left your keys—are becoming more frequent, mental exercises and a healthy brain diet may help. Just as bodies r...
A.
everyone can be forgetful sometimes regardless of one’s age
B.
we can prevent our sound mind from aging with certain methods
C.
brain aging starts from the time when we are in our 20s and 30s
D.
memory loss is a sign that shows we are getting old
【单选题】重金属（）
A.
在盐酸酸性条件下检查
B.
在硝酸酸性条件下检查
C.
在醋酸盐缓冲液（pH3.5）中检查
D.
在硫酸酸性条件下检查
E.
在磷酸盐缓冲液（pH6.8）中检查