肖邦的哪首作品抒发了他对波兰的留恋（） ["华丽大圆舞曲","降A大调波洛奈兹舞曲","E大调练习曲","升c小调玛祖卡"]
以下有关青霉素类抗生素的来源的叙述中，最正确的是（） ["发酵制造","半合成制造","全合成制造","由发酵液提取","由发酵液提取或半合成制造"]
零切粘度
建筑材料复试的取样中，工程的取样送检见证人，应由该工程（）书面确认，并委派在工程现场的建设或监理单位人员1～2名担任。 ["建设单位","承包单位","设计单位","监理单位"]
11. rbo = new ReallyBigObject（）； 12. // more code here 13. rbo = null； 14. /* insert code here */ Which statement should be placed at line 14 to suggest that the virtual machine expend effort toward recycling the memory used by the object rbo？（） [" System.gc（）；"," Runtime.gc（）；"," System.freeMemory（）；"," Runtime.getRuntime（）.growHeap（）；"," Runtime.getRuntime（）.freeMemory（）；"]
对辅导员的素质有什么要求？
