求翻译：2009年中美关系是晴空一片，人们对此记忆犹新，而进入2010年，两国关系却阴晴不定，甚至天刚放晴，就飘过来一朵乌云。是什么意思？

2009 China-US relations is a clear sky, people have remembered, and into 2010, bilateral relations have become increasingly volatile, even barely cleared, the drifting away to a dark cloud.

In 2009, Sino-US relations is a piece of the sky, and access to 2010 still fresh, and the relations between the two countries are cloudy, sunny skies uncertain, or even days just washed up on a flower, dark clouds.

In 2009 the Chinese and American relations is clear sky one piece, the people have a vivid memory regarding this, but enters in 2010, the relations between the two countries cloudy clear does not decide actually, even the day just cleared, fluttered dark cloud.

2009 Sino-US relations are clear, people still fresh, and 2010, the relations between the variable weather, or even just to clear up, a black cloud wafted over.

2009 Sino-US relations are clear, people still fresh, and 2010, the relations between the variable weather, or even just to clear up, a black cloud wafted over.