secondary constriction (次缢痕)
计算机常用的输入设备有() ["A、键盘、显示器、打印机","B、摄像头、鼠标、显示器","C、显示器、打印机、音箱","D、键盘、鼠标、扫描仪"]
kinetochore (动粒)
nuclease-supersensitive site (核酸酶超敏感位点)
一部电影的大小大约是1.1GB,要将这部电影保存到容量为650MB的光盘上,至少需要光盘的张数是() ["A、1","B、2","C、3","D、4"]
centromere (着丝粒)