php - Wordpress: Space between the slugs -

i have code display slugs of post:

<?php $terms = get_the_terms( $post->id, 'project-category' ); foreach($terms $term){ echo $term->slug; } ?> 

but sticky each other like:

cateogry-01cateogry-02

how can make like:

cateogry-01 cateogry-02

change:

echo $term->slug; 

to:

echo $term->slug . ' ';