A:②③④
B:①③④
C:①②④
D:①②③
1765年哈格里夫斯制造出“珍妮纺纱机”,1785年瓦特改良的蒸汽机投入使用。这些成果出现在( )
It is Henry Adams, an American businessman, ____ ____ ____ ____ London and does not know what he should do.