TheeconomyofDallas,Texas,isstronganddiversified.
A、inflatedInthenortheasternUnitedStates,itrainsintermittently间歇地throughoutthespring.
All living organisms, regardless of their unique identity, have certain biological, chemical, and physical characteristics in common.
AlthoughtheCarbon14methodofdatingoldobjectsisnotfoolproof,itisthebestmethodavailableatpresent
TheSalkvaccineisamajorfactorinthefighttoeradicatepolio.
Cream of tartar 酒石 , a weak acid, can be added to egg whites to help them foam泡沫 when they are beaten
