2) economical =cheap or not wasteful.
possibility的固定搭配:
possibility (that)
There's always a possibility that he might go back to Seattle.
possibility for/of (doing) something
exciting possibilities for reducing costs
Archer began to explore the possibilities of opening a club in the city.
错误搭配：possibility to do sth.
view固定搭配：
view sth. as sth.
而view sth. to be sth.错误。
announce固定搭配：
(1) announce something to somebody 或者 announce to somebody something (相当于宾语后置)
(2) announce a decision/intention/plan (在这个时候如果plan等后面接to do不会产生to do做状语修饰announce的歧义)*:The government has announced plans to create 10,000 new jobs.
(3) announce (that)
(4) announce somebody/yourself 通报...的到达;通知...已准备好(注意这个短语有专门意思)
错误用法：
(1) announce to do/be sth. 【错误】
limit的固定搭配：
n. : limit on sth.; limit to do sth.; limit for sb./sth.
There's a limit on the time you have to take the test.
The time limit for making claims is three months.
There's no age limit for applicants.
There's a limit to what we can do to help.
vt.: limit sb. to sth.; limit sth. (to sth.); be limited to sth
