1．it is said that the new chinese panda coin __ 99.9% goldAi

1．it is said that the new chinese panda coin __ 99.9% goldAis made up of
B is made out of
为什么不选A
不能说熊猫硬币是由99．9的金组成的吗
2．to taste; in good taste; with taste; on taste分别是什么意思啊
3．try to collect______
A as many stamps as possible
B stamps as possible as you can
为什么B 不对