refine format

doc/fluid/beginners_guide/install/compile/compile_Ubuntu.md

@@ -189,8 +189,8 @@
 	* 对于需要编译**GPU版本PaddlePaddle**的用户：(*仅支持ubuntu16.04/14.04*)
 
 		1. 请确保您已经正确安装nccl2，或者按照以下指令安装nccl2（这里提供的是ubuntu 16.04，CUDA9，cuDNN7下nccl2的安装指令），更多版本的安装信息请参考NVIDIA[官方网站](https://developer.nvidia.com/nccl/nccl-download):      
-			i. `wget http://developer.download.nvidia.com/compute/machine-learning/repos/ubuntu1604/x86_64/nvidia-machine-learning-repo-ubuntu1604_1.0.0-1_amd64.deb`
-			ii.  `dpkg -i nvidia-machine-learning-repo-ubuntu1604_1.0.0-1_amd64.deb`          
+			i. `wget http://developer.download.nvidia.com/compute/machine-learning/repos/ubuntu1604/x86_64/nvidia-machine-learning-repo-ubuntu1604_1.0.0-1_amd64.deb`     		
+			ii.  `dpkg -i nvidia-machine-learning-repo-ubuntu1604_1.0.0-1_amd64.deb`     		     
 			iii. `sudo apt-get install -y libnccl2=2.2.13-1+cuda9.0 libnccl-dev=2.2.13-1+cuda9.0` 
 		
 		2. 如果您已经正确安装了`nccl2`，就可以开始cmake了：

doc/fluid/beginners_guide/install/install_Ubuntu.md

@@ -87,8 +87,8 @@ Python3.5（该指令适用于本机未安装python2的用户，否则，请卸
 	* 对于需要**GPU版本PaddlePaddle**的用户：`pip install paddlepaddle-gpu` 或 `pip3 install paddlepaddle`
 	
 	> 1. 为防止出现nccl.h找不到的问题请首先按照以下命令安装nccl2（这里提供的是ubuntu 16.04，CUDA9，cuDNN v7下nccl2的安装指令），更多版本的安装信息请参考NVIDIA[官方网站](https://developer.nvidia.com/nccl/nccl-download):      
-			i. `wget http://developer.download.nvidia.com/compute/machine-learning/repos/ubuntu1604/x86_64/nvidia-machine-learning-repo-ubuntu1604_1.0.0-1_amd64.deb`
-			ii.  `dpkg -i nvidia-machine-learning-repo-ubuntu1604_1.0.0-1_amd64.deb`          
+			i. `wget http://developer.download.nvidia.com/compute/machine-learning/repos/ubuntu1604/x86_64/nvidia-machine-learning-repo-ubuntu1604_1.0.0-1_amd64.deb`     
+			ii.  `dpkg -i nvidia-machine-learning-repo-ubuntu1604_1.0.0-1_amd64.deb`       	 	          
 			iii. `sudo apt-get install -y libnccl2=2.2.13-1+cuda9.0 libnccl-dev=2.2.13-1+cuda9.0` 
 	> 2. 如果您不规定pypi包版本号，我们默认为您提供支持Cuda 9/cuDNN v7的PaddlePaddle版本。