1.Parentsaretaughttounderstandhowimportanteducationistotheirchildren'sfuture.此句中的how为什么不能用so来代替?可以说成"soimportanteducationis"(educationissoimportant)吗?
2.Afterwhatseemedlikehourshecameoutwithabittersmile.
此句中的what为什么不能用it?