Update quick_start_en.md (#576)

docs/en/tutorials/quick_start_en.md

@@ -68,13 +68,13 @@ cd ../
 ```shell
 export CUDA_VISIBLE_DEVICES=0
 python -m paddle.distributed.launch \
-    --selected_gpus="0" \
+    --gpus="0" \
     tools/train.py \
         -c ./configs/quick_start/ResNet50_vd.yaml
 
 ```
 
-The validation `Top1 Acc` curve is showmn below.
+The validation `Top1 Acc` curve is shown below.
 
 ![](../../images/quick_start/r50_vd_acc.png)
 
@@ -86,7 +86,7 @@ The validation `Top1 Acc` curve is showmn below.
 ```shell
 export CUDA_VISIBLE_DEVICES=0
 python -m paddle.distributed.launch \
-    --selected_gpus="0" \
+    --gpus="0" \
     tools/train.py \
         -c ./configs/quick_start/ResNet50_vd_finetune.yaml
 
@@ -116,7 +116,7 @@ Tringing script
 ```shell
 export CUDA_VISIBLE_DEVICES=0
 python -m paddle.distributed.launch \
-    --selected_gpus="0" \
+    --gpus="0" \
     tools/train.py \
         -c ./configs/quick_start/ResNet50_vd_ssld_finetune.yaml
 ```
@@ -131,7 +131,7 @@ Training script
 ```shell
 export CUDA_VISIBLE_DEVICES=0
 python -m paddle.distributed.launch \
-    --selected_gpus="0" \
+    --gpus="0" \
     tools/train.py \
         -c ./configs/quick_start/MobileNetV3_large_x1_0_finetune.yaml
 ```
@@ -148,7 +148,7 @@ Training script
 ```shell
 export CUDA_VISIBLE_DEVICES=0
 python -m paddle.distributed.launch \
-    --selected_gpus="0" \
+    --gpus="0" \
     tools/train.py \
         -c ./configs/quick_start/ResNet50_vd_ssld_random_erasing_finetune.yaml
 ```
@@ -185,7 +185,7 @@ Final training script
 ```shell
 export CUDA_VISIBLE_DEVICES=0
 python -m paddle.distributed.launch \
-    --selected_gpus="0" \
+    --gpus="0" \
     tools/train.py \
         -c ./configs/quick_start/R50_vd_distill_MV3_large_x1_0.yaml
 ```