A:1000mL,212g
B:950mL,543.4g
C:950mL,572g
D:500mL,286g
—Did you see _______ at the door? There is a boy waiting for you.
—No, I saw_______.
“神州5号”飞船上天后,需要和地面的人保持联系,也就是需要____,那就得用到____、____、____等通讯方式。