1£®To get students to master all the useful new words and expressions in this unit.

2£®To have students understand the new grammar item “the use of ‘it’” better£¬and enable them to use the following structures correctly£ºIt£«be£«(difficult/necessary/a rule/a duty)£«for/of sb.£«to do sth.£»It/This/That is£«the first/second time£«that sb.has/have done sth.£»It is/has been£«years/days/weeks since sb.did sth.£»It will be long/hours/days/years before sb.do/does sth.