有时候东西碎了，就无法再拼回去。
Collaboration across borders is key to solving global food security challenges.
构思得好的东西表达得也清楚，表达的文字也很流畅。
The security dilemma is a fundamental feature of international politics, as states' efforts to increase their own security often decrease the security of others.
The novel is the most complete expression of human freedom.
"Books are the windows to other worlds."
