We must ______ that the experiment is controlled as rigidly as possible.
A
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WhenIcamethroughthecustomsattheairport,Ihadtopay________onaclockIhadbought.
Othersarguethatsincetheearthhasenduredalongstringoficeagesinthelasttwomilliontothreemillionyears,anywarmingis________tobetemporary.
Constructionoftherailwayshelpedtodevelopthenational_______ofTanzaniaandZambia.
Theaddressbook________theemailaddressesofyourfriendsorgroupsofcolleagues.