________ several times，but he still doesn't know how to do it correctly.
| A．Although I've taught him |
| B．I've taught him |
| C．Having been taught |
| D．Having taught |
I failed in the job interview and only then _____ the importance of learning English well.
| A．I realized | B．I had realized | C．did I realize | D．had I realized |
The audience waited until the curtain rose and then laughter at the sight of the funny actor.
| A．burst out | B．burst into | C．broken into | D．began with |
The kind lady devoted all her life to _____ those homeless children.
| A．help | B．helping | C．be helping | D．being helped |
A new cinema here. They hope to finish it next month.
| A．will be building | B．is built | C．has been built | D．is being built |
Can you tell me the name of the company ______ you visited last week?
| A．/ | B．where | C．what | D．to which |