1 . His study was a mess with lots of books and magazines __________up everywhere.

A．to pile	B．having piled
C．piled	D．to be piled

2 . The researchers have discovered __________they believe to be a new species.

A．which

B．who

C．where

D．what

3 . Due to the light pollution, stars are too faint _________with naked eyes in the urban area.

A．observing	B．being observed
C．to be observed	D．to be observing

4 . He failed the driving test though he __________for a long time.

A．practises	B．has practised
C．was practising	D．had been practising

5 . An advantage of being the youngest child in his family is __________he gets a lot of attention.

A．that

B．whether

C．why

D．when

6 . —Oh, I __________my passport!
—Don’t worry. We have time to go back home and get it.

A．forget	B．forgot
C．will forget	D．had forgot

7 . It is more important than ever to develop one’s maths, science and computer skills _______technological change is accelerating.

A．though

B．unless

C．until

D．because

8 . ______ patient when you argue with someone who is not so reasonable.

A．Be	B．Being
C．To be	D．Having been

9 . Spending a few hours learning about the history and culture of the destination will help tourists understand      they're seeing

A．what	B．where
C．that	D．why

10 . You’d better prepare some candles at home          the power fails.

A．even though	B．in case
C．as long as	D．in order that