She tried to sleep, but thoughtsand images flashed into her mind.

He tried his best to solve the problem, 　　　　difficult it was.

of great importance _______ parents say and do in family life, which may have a life-long effect on their children.

(2013·潍坊一中期末测试) After the flooding, people were suffering in that area, ________ urgently needed clean water, medicine and shelter to survive.

it is to go to the seaside!