来来往往，保持联系，互相探望

1. coming and going, keeping in touch, visiting each other

noun (common) (futsuumeishi) noun or participle which takes the aux. verb suru intransitive verb

街道交通，高速公路

2. street traffic, highway

noun (common) (futsuumeishi) intransitive verb noun or participle which takes the aux. verb suru