I wonder if he ________ us, but I think if he ________ us, we'll be able to plete the task ahead of time.A.helps, helpsB.will help, helpsC.is helping, is helpingD.would help, has help
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B解析导解:前一个if意为“是否”,引导宾语从句,可用于将来时态.后一个if意为“如果”,引导条件状语从句,句中以现在时表将来.