變換車道需注意後方有無來車，並以信號手勢告知其他駕駛人注意

變換車道需注意後方有無來車，並以信號手勢告知其他駕駛人注意

結果 (英文) 1:

When changing lanes, pay attention to whether there is an incoming car behind, and use signal gestures to tell other drivers to pay attention

結果 (英文) 2:

When changing lanes, pay attention to whether there are incoming vehicles behind, and tell other drivers to pay attention with signals and gestures

結果 (英文) 3:

When changing lanes, you should pay attention to whether there is an oncoming car behind you, and tell other drivers to pay attention by signal gesture.