People ________ are not welcome here.

[　　]

A．smoking　　　　　　　　   B．smoked

Is this a ________ taxi?

[　　]

A．waiting　　　　　　　    　B．waited

The line is ________ to traffic on National Day .

[　　]

A．to open　　　　　　　   　B．to be opened

His face is familiar ________ all of us .

[　　]

A．with　　　　　　　　　    　B．to

－Let’s go to the observatory to learn about the origin of the universe.

－The origin of universe? I think it 　　　　　　   . No one so far can tell how.

[　　]

A．will never be explained

B．has ever been explained

C．was explained

D．is being explained

I am familiar ________ the facts.

[　　]

A．with　　　　　　　　　    　B．to

We often see musicians ________ in the streets.

[　　]

A．to perform　　　　　　　　    B．performing

－How did your hometown look like when you visited it last summer?

－My hometown is no longer ________ it was

[　　]

I'm looking after Tom today. He's been at my house ________ 8: 00 this morning.

[　　]

He made of millions of dollars at last, ________ himself the richest one in his family.

[　　]