太阳活动对地球的影响有 [ ]
A．干扰地面无线电短波通讯
B．在低纬度地区的夜空能看见极光现象
C．产生“磁暴”现象
D．诱发地震和火山爆发
AC
There was _____ I cared about how others may see me. Now I know how silly I was.
A．a time that
B．time that
C．time when
D．a time when
