The maths problem is ______ to work out.

[    ]

　　A. much diffcult　　 B. too difficult

　　C. enough diffcult   D. difficult enough

A computer can ______ a lot of problems quickly.

[　　]

A. work out　　B. put　　C. keep　　D. work

The math problem is ________ difficult for me ________ work out.

[　　]

同义代换(选出与画线部分意思相近的词语，使句意完整。)

The maths problem is too hard to work out.

[　　]

This problem is too difficult (困难的) for them ______.

[    ]

　　A. work out　　　　 B. work it out

　　C. to work it out   D. to work out