2 . Liberian President Ellen Johnson-Sirleaf -the first woman ________ to head an African country- said she did not expect to see a black American president in her lifetime.

A．elected

B．to elect

C．to be elected

D．electing

4 . The boy ________ in a white coat and carrying lanterns is my brother and the girl who ________ red costume is my sister.

A．dressed, wears	B．wearing, wears
C．dressing, wearing	D．wears, dressed

5 . Earth Day,________ on 22 April, is an annual event aiming to raise public awareness about environmental protection. And World Maths Day, ________ on 14 March, provides a special opportunity for education as it allows teachers to download online resources so their math classes can be fun and constructive at the same time.

A．marking, falling	B．marked, falling
C．marking, fallen	D．marked, fallen

6 . ______ to the discovery of black holes, Stephen Hawking is one of the most ______ scientists who have changed the way human understand the universe.

A．Devoted; admired	B．Devoted; admiring
C．Devoting; admired	D．Devoting; admiring

7 . It can be hard for you to imagine what trouble I have had _______ the problems _______ in the meeting held last week.

A．to deal with; refer to	B．dealing with; referring to
C．dealing with; referred to	D．to deal with; referred to