Replace the italicized parts in the following sentences with words or expressions from the following. underlying, a string of, energy conservation, renewable energy, thrive on, pose a threat to, hit an all-time high, at an unprecedented speed A report from the American Plastics Council (APC) shows that plastic bottle waste reached the highest level last year, with nearly 6 billion pounds ending up in landfills, incinerators or littered. Successful leaders in the 21st century will be those who not only learn from the past, but actually develop well through innovation and originality, encouraging risk-taking and divergent voices. The U.S, Government is seeking a record fine of $ 16 million against Toyota, the troubled Japanese carmaker, for deliberately hiding a defect linked to a series of accidents. Unless the real and fundamental causes of the problem are pinpointed and addressed, the problem keeps recurring. The A/H1N1 influenza has been spreading at a speed that has never been exceeded before , much faster than other pandemics in history, the World Health Organization (WHO) said on Thursday. With the gradual reduction of available fossil fuel reserves and the impact on the environment of fossil fuel use, engergy that can be naturally reproduced is becoming increasingly important. Simple things like turning off lights when you're not in a room and switching to cleaner sources of electricity like "green power" willhelp reduce carbon emission, so it's easy to make saving of energy part of your daily life. With the increasing volcanic ask cloud crisis across Europe, there is also growing concern about whether these pparticles of rock and dust in the air are dangerous to public health.