Complete the sentences with the missing words.

Даны эти слова: lie, lies, flow, flows, flowed, stretch, stretched.

1) Washington, D.C. ... on the Potomac River. 2) The Great Plains ... to the east of the Rocky Mountains. 3) The Volga ... from the Valdai Hills to the Caspian Sea. 4) The road ... ahead for miles. 5) Did the river ... into the sea? --- No, it didn't. It ... into the lake. 6) Kazan and Samara ... on the Volga.

Help me, please!