奥巴马召集民主党人谈大选

词汇讲解：
1. annual adj. 每年的, 年度的, 一年一次的
例句：The grandfather had assembled all the members of the family for the annual picnic.
祖父把一家人聚在一起进行一年一度的野餐。

2. ovation n.热烈欢迎
例句：She received a tremendous ovation.
她受到了极其热烈的欢迎。

3. sharpen vt. (使)变得更好；提高某人(或事物)的水平(或技术、效率等)
例句：This exercise will help students sharpen up their reading skills.
这个练习将帮助学生提高阅读能力。

4. strained adj.紧张的;不友善的；勉强的;态度不自然的
例句：Relations between the two countries had become severely strained.
两国关系已经变得非常紧张。

5. negotiation n.协商, 谈判；完成(难事);通过
例句：The proposal is now under negotiation.
目前正在就这项提案进行磋商。

6. accomplish vt. 达到(目的)；完成(任务、使命、计划、事业等)
例句：This task is accomplished by great effort.
这项任务是经过巨大努力才完成的。

7. absence n. 缺乏, 不存在
例句：A major problem is the absence of water.
主要的问题是缺水。

8. compromise n. 妥协, 折中方法
例句：The spokesman made it clear that no compromise was yet in sight.
发言人表明, 目前还不会妥协。

9. obstruct vt.阻塞; 堵塞；阻碍, 阻止, 妨碍
例句：Tall trees obstructed his view of the road.
有大树挡着, 他看不到道路。

10. notion n. 概念, 观念, 看法
例句：One common Chinese notion is that the elders ought to be respected.
中国人共有的一种观念是长者应受到尊敬。