be动词后的宾语to do和doing都行吗
为什么有时用to do有时用doing但是我见过的大多数都是doing 有什么区别吗?
还有一个问题 If you tell a friend you are going to their house for dinner为什么用theirZ不用his or her?【课本原句】
还有这个句子If someone invites you to meet them at 4:00也是一样的情况，也是课本原句。