27.After the bell rings, which indicates the ending of the exam, you ______stay where you are until all your papers are collected.
Kevin was not good at Chinese at first. After two months in China, _____, he made great progress.
The worst tornado of all time occurred in 1925, ______ three US states.
______ right in the center of the city, the park attracts a lot of tourists.
Physics ________ my favorite subject. I like it so much that I wish we had a physics class every day.
Good care must ______ these children, especially when they are ill.