toughening

"My friend told me there was something in the box, but I didn't know what it was yet. "

"The competition for this job is strong."

"The student was a strong resistant, leading the group in their peaceful protest against the unfair school rules. "

"It is hard work to swim against the current."

"The store is offering a special on school supplies this week. "

"She trained seven hours a day to prepare for the Olympics."

"The school's track and field team has many dedicated athletes. "

"The tent, made of tough canvas, held up to many abuses."

"The upcoming school holiday is a welcome break for the students. "

"The process of baking a cake involves several steps, from mixing the ingredients to putting it in the oven. "

"The small dog underwent the tunnel to get to the other side of the park. "

"The complicated instructions on the new software difficult me from completing the project on time. "