___\_is a relatively complex form. of compounding in which a new word is formed by joining the initial part of one word and the final part of another word. For example, the English word smog is made from___\_and______.

A word formed by derivation is called a___\_, and a word formed by compounding is called a______.

Back-formation

简述整群随机抽样的适用条件和优缺点。

A number interesting word-formation processes can be discerned in the following examples. Can you identify what is going on in these？ （a) The deceased s cremains were scattered over the hill. （b) He s always taking pills, either uppers or downers.

简述分层随机抽样的适用条件和优缺点。