4．
(1) I look back on my time in the UK ___________ ___________(满意地)，and I really hope to go back and study there again.
(2)Daniel _______ _________ ________ (迫不及待) put on his new shoes.
(3) You had better find the best way to ________ ________ _________ _________(充分利用) the materials.
(4) It was raining heavily, but he ________ _________(坚持) going there.
(5) Boys ________ ________(倾向于) become risk-takers when they are teenagers.