Land development and agriculture are just two uses of natural resources that change and destroy environments that birds need.

VOA: special.2009.05.12

So, let's change our graph where we now have this zero point set as the two individuals hydrogen atoms, and then we see that our h 2 molecule is at the negative of the dissociation energy, or the negative what that bond strength is.

那么让我们把曲线图中的零点能改到,两个分离的氢原子处，那我们就会看到,氢分子就是负的离解能，或者负的键的强度。

麻省理工公开课 - 化学原理课程节选

Today we tell about two women who helped change the world of sports, golfer Betty Jameson and basketball coach Kay Yow.

VOA: special.2009.03.29

We also will tell about two studies of seabirds, and how a change of color could help fight rising temperatures.

VOA: special.2010.03.02

The goal of this event is to demand that lawmakers pass new legislation on climate change and clean energy in two thousand ten.

VOA: special.2010.04.21

Two rulings in the United States could change how information is controlled online and in our bodies.

VOA: special.2010.04.09

The two still have a lot more they want to accomplish, including financial reform, immigration reform, and climate change legislation.

VOA: standard.2010.05.11

"Time is up," "Over the next two weeks, governments have to deliver a strong and long-term response to the challenges of climate change."

VOA: standard.2009.12.06

On the subject of North Korea, ElBaradei said there are two key issues: "One is its obsession with security and the possibility of regime change by the U.S.

VOA: standard.2009.11.04

The two leaders also discussed the nuclear situation in Iran, the world economy and global efforts to fight climate change, After meeting with the German chancellor, Mr.Obama was to take part in the U.S.-European Union summit at the White House.

VOA: standard.2009.11.03