Holonyak's colleagues thought he would fail in his research on LEDs at the time when he started it.

• A、True
  
  

• B、False
  
  

• C、Not Given
  
  

According to the passage, which aspect of skyscrapers were some residents of North America concerned with in the late 1960's?

• A、The poor reception of radio and TV signals.
  
  

• B、The removal of trees and grass from building sites.
  
  

• C、The harmful effects on the city's plans.
  
  

• D、The obstruction of air traffic
  
  

假設(shè)你的美國朋友Mike要去你的家鄉(xiāng)旅游，請(qǐng)給他寫一封電子郵件，告訴他:

1. 近期的天氣情況；

2. 需要注意的事項(xiàng)；

3. 你期待與他見面。

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