It is only ________ from my home to the school.

[　　]

A．a 20 minutes' walk

B．a 20-minutes walk

C．a 20 minute walk

D．a 20-minutes' walk

He used to live in ________.

[　　]

A．a six-storeys building

B．a building of six floored

C．a six-floors' building

D．a building of six storeys

In such dry weather the flowers will have to be watered if they ________.

[　　]

-- You are so lucky.

-- What do you mean ________ that?

[　　]

In some parts of London, missing a bus means ________ for another hour.

[　　]

80 percent of the population in our country ________ peasants.

[　　]

Our country has a ________ population than the USA.

[　　]

The ________ have become a bother to the government.

[　　]

A．unemployed

B．unemployment

C．employing

D．unemployment workers

-- How long ________ at this job?

-- Since 1990.

[　　]

A．were you employed

B．have you been employed

C．had you been employed

D．will you be employed

It's difficult to find a ________ place in the downtown of the city.

[　　]