In the words unhappy and unusual，the "un" means _________．（ ）
A．veryB．mostC．notD．less
As we know，sixteen﹣year﹣olds_____drive a car in our country.（ ）
| A． |
must |
B． |
could |
C． |
mustn't |
D． |
couldn't |
I usually spend time_____in the library on weekends.（ ）
| A． |
read |
B． |
reading |
C． |
reads |
D． |
to read |
Jack is quite different_____his twin brother Jeff.（ ）
| A． |
to |
B． |
for |
C． |
from |
D． |
with |
Katie is_____of the three girls in her family.（ ）
| A． |
young |
B． |
younger |
| C． |
the younger |
D． |
the youngest |
Our classroom won't be clean _____we clean it every day.（ ）
| A． |
after |
B． |
while |
C． |
unless |
D． |
because |