be used as 被当作...用
be used for 被用来干...= be used to do
be used to doing 习惯做...=get used to
it's no use doing sth 做...是没用的.
sth is of use to sb 某物对于某人很用用.
come into use 开始使用
make use of 使用、利用
不然会生气!