Of the two sisters, Betty is_______ one, and she is also the one who loves to be quiet．
| A．a younger | B．a youngest | C．the younger | D．the youngest |
The rich ____ not always happy.
| A．are | B．is | C．has | D．have |
I, who____ your friend, will try my best to help you with your English.
| A．am | B．is | C．are | D．be |
The United States of America _____one of the most developed countries in the world.
| A．is | B．are | C．was | D．were |
The whole class _____the teacher attentively.
| A．are listening to | B．is listening to | C．are listening | D．is listening |
Jane is one of the best students in her class who _____by their teacher.
| A．are praised | B．is praised | C．praised | D．praising |