A:would have arrived
B:arrived
C:must have arrived
D:should arrive
__________Lei Feng is no longer living, his spirit lives on today.
如图表示一种光学仪器的原理,图中L1是物镜,L2是目镜.这种仪器是____(填“望远镜”或“显微镜”),目镜的作用相当于____(填“放大镜”或“投影仪”).
如图为南半球经纬网示意图,丁地的经度是( )