Men make a thousand sperm every second and to have an effective contraceptive, 每秒中，男性可生产出一千个精子，所以有效的避孕药 you need to get that level of sperm production down to one percent of its normal value. 必须把这个精子生
PRESIDENT OBAMA: Well, I just had an excellent discussion with President Lee and his team. Obviously we are marking the 60th anniversary of the Korean War and the extraordinary friendship and alliance
THE PRESIDENT: Good morning. Over the past few days, we have witnessed a startling drop in the stock market -- much of it driven by uncertainty and fear. This has been a deeply unsettling period for t
