I know one of the things I was unsure about was _____ hard it would be to climb this mountain.

My father is ill, I have to look after him at home.—

Look! So many colorful bicycles in two lines over there.—They’re for public. This ______ of green smart traffic is everywhere in Xiangyang city.

Have you seen film Amazing Spider-Man2— Yes, I found it exciting one!

Mr. Park, I know I am late, but please allow me to explain it to you, ________？