1.has been away;for2.Why do you3.How long4.How many5.What does;collecting6.--Have you been learning English for two years?--No,I haven't.7.He hasn't been writing a letter to his parents since three o'clock.8.What has your mother been doing for about ten years?9.They kept playing in the park for three hours.10.How long has Mary been waiting for the school bus?
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