_____ we continue to kill elephants for their ivory，we humans will lose them in the end．（ ）
| A． |
If |
B． |
Before |
C． |
Until |
D． |
Although |
My grandfather does Chinese Kung Fu every day _________ he is over eighty． （ ）
A．sinceB．thoughC．until
May I be allowed to choose a summer course？
It's up to you． You're ____ to make your own decision． （ ）
A．too oldB．enough oldC．old enough
I saw Tom's father bought lots of books yesterday．
That's not strange． Not only Tom but also his father _______reading． （ ）
A．enjoyB．enjoysC．enjoyed
Do you know when and where the 24 Winter Olympic Games___________？
In Beijing and Zhangjiakou， in 2022． （ ）
A．is heldB．will be held
C．will hold
Sally， it's already 10： 00 pm． It's time for you to go to bed．
OK． Dad． I'll turn ________ the TV right now． （ ）
A．onB．downC．off