Recent security measures can present new obstacles for parents and children.
The march, then, under the trees, would not present obstacles.
Or, at the least, playing in this manner they'll present an obstacle to other teams.
And that would present a major obstacle, no matter how many games the Yankees win in the regular season.
While witnesses are usually crucial, they sometimes can present obstacles.
The vegetation itself is often dense enough to present an obstacle.
The river presents natural obstacles in the form of light rapids.
But the nation's trade ban against China presented a mighty obstacle.
That's going to present a very significant obstacle to this whole procedure.
Differences in educational/teaching styles, language, and culture may present further obstacles to international students who apply to American programs.