ecause of 不接句子接相当于名词的词
省略式完整为to learn how to ride a horse
定语从句介词放在关系代词的前面比较正式
中间有插入语,不看插入语,句子为I hope the dialogue__要用不定式的被动语态_______ between the two presidents next week will give us some active signal.
一般用 for lack of ,lack为及物动词
因为定语从句如果which 表示所属就只能是of which原句=The book whose cover is torn is mine