A:was; had
B:would be; had had
C:would have been; had
D:would be; had
“凤阳地多不打粮,碾子一住就逃荒”,“改革鼓点先敲响,如今飞出金凤凰”。这两段《凤阳花鼓》词中安徽凤阳农民生活的变迁与下列哪一政策息息相关( )
如图,为估算某河的宽度,在河对岸选定一个目标点A,在近岸取点B,C,D,使得AB⊥BC,CD⊥BC,点E在BC上,并且点A,E,D在同一条直线上.若测得BE=20m,CE=10m,CD=20m,则河的宽度AB等于( )
依据图对米勒模拟实验的解释你不认同的是( )