44. How did Benedictus feel when he saw thecracked glass flask? A. Angry.B. Sorry.C. Excited.D. Surprised. 45. The glass flask didn’t fall apart because___. A. the floor was not so hard B. the shelf was not so high C. there was dried plastic in it D. Benedictus’ helper c...
2. Shatterproof Glass Was Invented by Accident. French chemist Edouard Benedictus inadvertently invented shatterproof glass when he dropped a glass flask coated in cellulose nitrate. Why do glass blowers draw on the floor? Often, his day begins with a chalk drawing on the floor, conveyed in the...
Rene Theophile Hyacinthe Laënnec (1781-1826) was a French physician who, in 1816, invented the stethoscope. Using this new instrument, he investigated the
The valley of ashes is bounded on one side by a small foul river, and, when the drawbridge is up to let barges through, the passengers on waiting trains can stare at the dismal scene for as long as half an hour. There is always a halt there of at least a minute, and it was beca...
No, what we found was that if you install a lot of unreliable wind, you are forced to install essentially the same amount of gas generation that can be spun up fast. So the real cost of your wind electricity is almost double due to back up costs. Then if you are reliant on gas gen...
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