Train tickets_____online． It is convenient．（ ）
| A． |
sold |
B． |
were sold |
C． |
are sold |
D． |
have sold |
I bought my mother some flowers on Mother's Day．（ ）
A．直接宾语B．间接宾语C．表语D．状语
It is our duty to protect the environment．（ ）
A．直接宾语B．间接宾语C．形式主语D．真正主语
The quiet music makes me relax．（ ）
A．宾语B．状语C．宾补D．定语
The food in the restaurant is delicious．（ ）
A．表语B．宾语C．主语D．谓语
I visited the zoo last Sunday．（ ）
A．主语B．谓语C．状语D．宾语