宇航员取回了一块月岩样本.Astronauts brought back a piece of the moon.1993年, 一块苏联的月岩标本在苏富比拍出了$442, 500的高价.S . government property . At Sotheby's in 1993, a Soviet sample fetched $ 442, 500....
Television broadcasters were warned to exercise caution over depicting scenes of violence.电视台受到警告，要求对暴力场面的描绘采取谨慎态度。Commercial radio broadcasters have used long waves for nearly 60 years.将近60年以来,民用的无线电广播一直用的是长波.Patriot br...
Marconi now found that he could transmit Morse Code signals.他现在可以用它来发送和接收莫尔斯电码了.This third demonstration was naturally a very important one for Marconi.当然,这次实验对马可尼来说十分重要.We owe it to Marconi and Bell that we can now talk...