Underline the correct item

1) By the time Graham arrived at the train station, the train had already left.2) How long had you been trying to call Tom before he finally answered the phone.3) The children had put away their toys before their mum came back home.4) Alan had a headache because he had been playing computer games all afternoon.5) Simon had been saving money for many years before he bought his own house.6) The football game had just started when it began to rain.