is of great importance这是什么语法点?为什么is 后面加了of

is of great importance这是什么语法点?为什么is 后面加了of Confident is of great importance! English is of great importance ___with ,the course is of great importance. the question _____tomorrow is of great importance 翻译"The matter is of great importance." This question is of great importance this matter is of secondary importance为什么这句话中,要加of? the meeting is (of great importance )请问为什么括号里的不能换成 great imp conservation of water is of great importance in desert areas A highly _____________general manager is of great importance 作业>>单选题1：The question______yesterday is of great importance.