印度尼西亚的矿产和热带作物丰富,如 等矿产在东南亚产量和出口居首位。
锡
—Is Bill in?
—No, he _______ to the railway station. [ ]
A. has gone
B. had gone
C. has been
D. had been
碘缺乏病是目前已知的导致人类智力障碍的主要原因.为解决这一全国性问题,我国很久以前就已经开始实施“智力工程”,最经济可行的措施是( )
A.食盐加碘(盐)
B.面包加碘(盐)
C.大量食用海带
D.注射含碘药剂