世界人口稠密地区往往分布于()
Hebuiltatelescope____hecouldstudytheskiesinhisfreetime.
Hiscompanionshavethreatenedto__hiscrimestothepolice.
It’syourjob________thepopstars.
Thankyouforyourhelp,_____wecouldnothavefinishedtheworkintime.
Thedoctor____isleavingforAfricanextmonth.