fold up垮掉；放弃；倒闭
fold up into折叠起来成……
follow out贯彻、执行……；把……探究到底
follow up把……探究到底
follow up sth．with用继续行动等加强……的效果
fool sb．into＋v－ing（phr．）哄骗某人做……
fool sb．out of sth．诈骗某人的……
force sb．into＋v－ing（phr．）强迫某人做……
forgive sb．for＋v－ing（phr．）原谅某人做的事
frighten sb．into/out of＋v－ing（phr．）使某人吓得做（不做）……
