They have thrown rubbish everywhere. He has done the cleaning. Last summer we were at the sea side. My friend has cut down that tree already. People have polluted the air. That old factory polluted the river. They fought against nuclear weapon. Our planet has given us food and clothes. They were glad to see that animal. Identify the tense form
They ……… ………. (kill) millions of fish already. Yesterday the cloud …………. (look) like a white sheep. They ……….. ……….. (already, cause) different problems. He ……… ……….. (just, find) the solution of the problem. The day before yesterday, they …………. (discuss) the problem of the pollution. Put the verbs into correct form