impervious

"The apéritifs were particularly stimulating."

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

"The new policy, surprisingly, unaffected the students' daily routines. "

"The rain jacket is made of an impermeable material, so you won't get wet even in a heavy downpour. "

"Please completely fill in the box for your answer, using a number 2 pencil."

"Although it was very muddy, the football game went on."

"The flu shot is a preventive against getting sick. "

"A line or cable supported by its ends sags, even if it is tightly drawn."

"The experience affected me deeply."

"The fortress is impenetrable, so it cannot be taken."

"The student's deception about completing the assignment led to a disappointing grade. "

"Any penetration, however slight, is sufficient to complete the offense."