insurmountable

"The train passed through the tunnel. "

"The being in the classroom was quiet today. "

"The incapable student struggled to complete even the simplest assignments. "

"She is getting her daughter a puppy for her birthday. "

"She surmounted her fear of public speaking and delivered a fantastic presentation. "

"The difficulty of the math problem made it hard for many students to solve it. "

"The song's constant worry about failing the exam was its main overcome. "

"The bowling team scored a lot of points with their final over. "

"The financial crisis presented an insuperable obstacle to starting a new business. "

"The teacher proved the student's essay before returning it, marking any grammar errors. "

"all parties agree in the expediency of the law."

"Everybody in the class needs to bring their homework tomorrow. "