Misc: who wrote the opera 'tosca'?

Questions

After his death in 1937, Guglielmo Marconi, inventor of the ___________ was honored by broadcasters worldwide as they let the airwaves fall silent for two minutes in his memory?

Artificial rain was first used near _______, New Hampshire, in 1947 to fight a forest fire?

At a glance, the Celsius scale makes more sense than the Fahrenheit scale for temperature measuring. But its creator, Anders Celsius, was an oddball scientist. When he first developed his scale, he made freezing 100 degrees and boiling 0 degrees, or upside down. No one dared point this out to him, so fellow scientists waited until Celsius died to change the scale. True or False?

At a jet plane's speed of ______ miles per hour, the length of the plane becomes one atom shorter than its original length?

Bill Gates formed a company to sell a computerized traffic counting system to cities, which made $20,000 its first year. Business dropped sharply when customers learned Gates was only _______ years old?