【单选题】自然光以入射角 56 ° 由空气投射于一块平板玻璃面上,反射光为完全线偏振光,则折射角为:
【单选题】While we _________, we saw a UFO land on a street.
【单选题】单项选择。 We want you with us. [ ]
【单选题】During the storm we took ______ in the doorway of a shop.
【简答题】We have such a variety of (choose) ______ when we go to a card shop.