投入

to throw into / to put into / to throw oneself into / to participate in / to invest in / absorbed / engrossed

to cast / to send / to throw oneself (into the river etc) / to seek refuge / to place oneself into the hands of

to enter / to go into / to join / to become a member of / to confirm or agree with / abbr. for 入聲|入声[ru4 sheng1]