1 . She built her success on a solid ________ of hard work, determination, and a passion for her craft.

A．device

B．charge

C．source

D．basis

2 . With each passing year, he grew more ________, displaying a better understanding of the world around him.

A．mature

B．artificial

C．impressive

D．beneficial

3 . The sleeve of my jacket (got) caught on the door handle and ________.

A．broken

B．crushed

C．ripped

D．crashed

4 . To transfer information from short-term to long-term memory, the ________ requires periods of rest.

A．heart

B．spirit

C．brain

D．head

6 . It is 10 years ________ these important environmental problems were addressed, which benefited the entire world.

A．since

B．after

C．before

D．when

7 . ________ the grandparents love the children, they are strict with them.

A．While

B．As

C．Since

D．Because

8 . The students, who had been studying for their exams for months, were ________ the night before the exam, trying to remember as much information as possible.

A．marching

B．cramming

C．burning

D．pressing

9 . Over-exercising is very dangerous ________ it adds too much burden to the heart.

A．even if

B．although

C．because

D．unless