在非相干解调方式中,常用的有()、()以及()。
参考答案:单滤波器检测法;双滤波器检测法;鉴相器检测法
When very small dinosaur bones were found in a Germany mine, people thought they were from baby dinosaurs. ___小题1:_ Martin Sander's work shows that they were probably fully __小题2:__ (grow) and belong to the smallest giant dinosaur species ever found.
Growth marks on dinosaur bones are similar __小题3:__ growth rings on trees. The rings are far apart while the animal is young and growing quickly. __小题4:__ get closer as growth slows. "It is _小题5:__ (exact) these tight ring marks that we found in the fossil bones," says Sander. So the fossils must have been from adult animals.
__小题6:__ was this German dinosaur so much smaller than other giant dinosaurs, which grew up to 45 metres long and weighed as much as a thousand humans?
150 million years ago, most of Germany was underwater. Scientists think that __小题7:__ water levels rose, there was less and less land and food available. The dinosaur _小题8:__ (need) less space and food.
Since 1998, scientists have dug up more than 1,000 dinosaur fossils in the mine. It is one of the few places in the world __小题9:_ the bones and footprints of dinosaurs have been found together.
上手术台前手术人员的术前准备有哪些