4．
(1).The president _________ (辞职) from the company because of his poor health.
(2).To my _____________ (满意), my son has made great progress in his lessons.
(3).The rich man ___________ (抛弃)his wife and children.
(4).We _____________ (参加)in voluntary work during the earthquake.
(5).I will ___________ (推荐) you to the manager of our company.
(6).There are some _________ (可选择的) courses for you.
(7).Of the first Spanish to go to California, the __________ (大多数) were religious men.
(8).Their miserable stay seemed to be punishment rather than _______ (公平,正义).
(9).Cloning plants is ______ (简单的;直接的)while cloning animals is very complicated.
(10).Gardeners use it all the time to produce ________ (商业的;贸易的) quantities of plants.