20世纪70年代以来西方政坛和思想界的政治思潮呈现（）、（）和（）趋势。
参考答案：深化；多样化；相互交融
— I hear Tom is working hard at his lessons.
— I'm _____ he will pass the exams this time. [ ]
A. afraid
B. surprised
C. sure
D. sorry
试述绵马贯众的来源、产地、叶柄基部横切面显微特征？
