Put the cleaned fish in a mixture of 300g of salt and one liter of water to ________ all of the blood from the fish meat.

A．replace

B．remove

C．calculate

D．spoil

甲、乙两校原有人数的比为6∶5，甲校毕业了200人，乙校毕业了125人后，两校人数的比为8∶7。原来两校各有多少人？