1 . To protect my computer from _____(attack) by hackers, I equipped it with anti-virus software. （所给词的适当形式填空）

2 . Our Chinese government strongly opposed ________ (release) the treated radioactive wastewater from the ruined Fukushima Daiichi Nuclear Power Plant into the Pacific Ocean. (所给词的适当形式填空)

3 . He contacted charity organizations about rebuilding the playground and________ (set) up a library, and helped the villagers sell local products online. （所给词的适当形式填空）

4 . The approach to ________(simple) the complex social welfare system seems a success, making it easily accessible to every citizen. (所给词的适当形式填空）