Petroleum is a fossil fuel derived from ancient fossilized organic materials, such as zooplankton and algae. Vast quantities of these remains settled to sea or lake bottoms, mixing with sediments and being buried under anoxic conditions.
To create a poll and share it with your Twitter followers, go to TwitPolls (see link at the end of this post), login and authorize your Twitter account and click Create. This will display the necessary options to create a poll. You can also add an image and select a time frame after which the poll is closed.
Blocking followers on Twitter is not a matter of government censorship, but rather of expressive freedom to listen and speak. The president can decide if he wants to hear out the public in person, on the phone or online. The choice to block is no different from a decision to decline an invitation to a conference.