These animals are in danger.We should think ______ to protect them.
A:how we can do
B:how can we do
C:what we can do
D:what can we do
下图中GH⊥PQ,据此完成下列各题。
恩格斯称下列哪一历史人物“是中世纪的最后一位诗人,同时又是新时代的最初一位诗人”?( )