The National Zoo said Wednesday that China has granted an extension of its lease of Washington's two giant pandas, Mei Xiang and Tian Tian.
美國國家動物園在周三表示，中國已經(jīng)同意延長華盛頓的兩只大熊貓梅香和天天的租期。

Zoo Director Dennis W. Kelly was in China last week seeking to negotiate a new panda arrangement to replace the 10-year, $10 million lease that expired Dec. 6. China owns and leases all giant pandas in U.S. zoos.
動物園園長丹尼斯 W·凱利上周來到中國協(xié)商新的熊貓租借方案來代替在12月6號到期的一千萬租借大熊貓十年的租約。中國仍然對美國動物園里租借的所有熊貓享有擁有權(quán)。

The zoo badly wants cubs for research purposes. And recent science suggests that if a female panda has not become pregnant for several years, it is increasingly unlikely that she will be able to get pregnant in the future.
處于研究目的，園方十分希望能夠獲得熊貓幼崽。但是最近科學家認為如果一直雌性熊貓長年都未懷孕的話，那么在之后的時間中懷孕的可能性就更小了。

"We've not had a cub here in the last five years," Kelly said in an interview in July.
“過去五年中我們都沒有熊貓幼崽，”凱利在7月的一次訪問中說。

"There's some data that suggests that after four [breeding] tries, there's something [negative] going on," he said in July. Pandas generally mate once a year.
“一些資料表明，在之前的四次（繁殖）努力失敗后，存在著一些不利因素，”他在7月的采訪中說道。熊貓一般每年只交配一次。

Zoo scientists are planning for Mei Xiang's upcoming breeding season. She went into heat last Jan. 9 and Jan. 15 the year before. And the zoo said it would not move her during her annual pregnancy watch, which usually lasts until spring.
動物園的科學家們正在為梅香的下一個繁殖期做準備。她在去年的發(fā)情期是在1月9號和15號。動物園方面說，從對她每年的懷孕期的觀察看來她發(fā)情期的時間應(yīng)該是穩(wěn)定的，她的發(fā)情期通常會持續(xù)到春季。

The Memphis Zoo's panda pair, residents there since 2003, have not produced any offspring.
孟菲斯動物園的一對大熊貓從2003年入園以來目前還未產(chǎn)子。