Three Roads to Quantum Gravity

• 量子重力

Three Roads to Quantum Gravity的用法和样例：

例句

1. A quantum theory of gravity is needed.
   这时候你需要量子重力理论才行。
2. Many open questions remain to be answered in loop quantum gravity.
   还有许多悬而未决的问题，正等著环圈量子重力来回答。