— What did your father do yesterday?
— He ________ at home and read a book.
A:stay
B:stayed
C:is staying
D:stays
①价值尺度 ②流通手段 ③贮藏手段 ④支付手段
农谚“有收无收在于水,收多收少在于肥”,这种说法符合科学种田。