They have ________ the cause of the accident, but the result is still not known to us.

[　　]

Do be quiet! I'm trying to hear what the speaker ________.

[　　]

As your spoken English gets better, ________ your written English.

[　　]

I'd like to listen to VOA program but sometimes I can't ________ on my radio.

[　　]

His invention ________ of no use by the scientists of that time.

[　　]

Rose was wild with joy ________ the result of the examination.

[　　]

As we know, the 2008 Olympic Games will ________ in Bering, China.

[　　]

________ lessons were not very difficult.

[　　]

You can fully trust her. She graduated from a ________ college with five years' experience of treatment.

[　　]

That ________ is a director of our factory.

[　　]