In our country, there are a lot of theories about mural and environment art.

在我国，关于壁画、关于公共环境艺术的理论有很多。

youdao

In the last fifty years, there have been a lot of theories generated about how to do this.

在过去的五十年中，产生了许多关于如何这样做的理论。

youdao

There are a lot of theories about what causes them, but scientists have not been able to prove exactly why they occur.

对于抽筋产生的机理目前有很多的理论，但科学家们仍然不能确切地证明抽筋为什么会产生。

youdao

There are a lot of theories -- nobody really knows what causes it.

CNN: Smoking quadruples risk for vision-stealing eye disease

We have had a lot of theories about what causes leukaemia, but this study takes us to a very firm conclusion.

BBC: NEWS | Health | Day care prevents child cancers

"There are a lot of different theories of how to reduce the musculo-skeletal problem - this is a different take on it that looks pretty promising, " Prof Newman said.

BBC: Gravity suit mimics Earth's pull for astronauts