Having been capital of a vast pre-Hispanic empire, and also the capital of richest viceroyalty within the Spanish Empire (ruling over a vast territory in the Americas and Spanish West Indies), and, finally, the capital of the United Mexican States, Mexico City has a rich history of artistic expression. Since the mesoamerican pre-Classical period the inhabitants of the settlements around Lake Texcoco produced many works of art and complex craftsmanship, some of which are today displayed at the world-renowned National Museum of Anthropology and the Templo Mayor museum. While many pieces of pottery and stone-engraving have survived, the great majority of the Amerindian iconography was destroyed during the Conquest of Mexico.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): When did the complex art of Mexico City begin?
Ah, so.. pre-Classical period

The bank must also co-operate within the EU and internationally with third bodies and entities. Finally, it contributes to maintaining a stable financial system and monitoring the banking sector. The latter can be seen, for example, in the bank's intervention during the subprime mortgage crisis when it loaned billions of euros to banks to stabilise the financial system. In December 2007, the ECB decided in conjunction with the Federal Reserve System under a programme called Term auction facility to improve dollar liquidity in the eurozone and to stabilise the money market.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Who rejected, along with the ECB, to use Term auction to help stabilize the financial crisis and improve dollar liquidity?
Ah, so.. unanswerable

Portuguese pavement (in Portuguese, Calcada Portuguesa) is a kind of two-tone stone mosaic paving created in Portugal, and common throughout the Lusosphere. Most commonly taking the form of geometric patterns from the simple to the complex, it also is used to create complex pictorial mosaics in styles ranging from iconography to classicism and even modern design. In Portuguese-speaking countries, many cities have a large amount of their sidewalks and even, though far more occasionally, streets done in this mosaic form. Lisbon in particular maintains almost all walkways in this style.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Which city has almost all of its sidewalks in Portuguese pavement?
Ah, so..
Lisbon