Every day students in our school will do outdoor activities ______ there is a heavy haze(雾霾).
| A．unless | B．while |
| C．until | D．since |
Is this ________ elephant or _______ lion?
| A．a; an | B．the, the | C．an ; a | D．an; the |
Let’s play tennis!—. I need to go to school today.
| A．That sounds good. | B．No, it’s interesting. |
| C．Yes, thanks. | D．Sorry, I can’t. |
—What’s favorite subject?
—My favorite subject is math.
| A．you | B．your | C．I | D．me |
Bob's mother is my aunt. He is my ______
| A．uncle | B．brother | C．friend | D．cousin |
I don’t like science _____ it’s difficult.
| A．so | B．but | C．and | D．because |