1 . With his attention      on the shop along the roadside, he knocked an old man down while riding to school.

A．concentrating	B．concentrated
C．having concentrated	D．to concentrate

2 . In the past few months, the man has been c________all his efforts on finding a solution to the problem. (根据首字母单词拼写)

3 . She was so        in her work that she didn’t realize it was time to pick up her son.

A．attracted

B．considered

C．absorbed

D．concentrated