wouldliketo/wantto
1.Theyshouldbeallowedtopracticetheirhobbiesasmuchastheywant.
2.Theywon'tallowhimtotrainasmuchashewouldliketo.
3.Youcankeepquietifyouwantto.
为什么2,3后面有to,而1没有?是否可以加上
4.Healwaysthinksmoreofhimselfthanofothers.
第二个of是否可以省略.
还有类似的and连接的to,为什么有的句子前后两个to,而有的后面省略了.