The three leading contenders were locked in a dogfight.三名领先的竞争者陷入一场鏖战。The leading contenders are still slogging it out.处于领先位置的竞争者仍在激烈地角逐。The contenders faced off the debate at Iowa State University today.今天,竞选者在爱荷华州立大学展开...