（Ⅰ）请在图中作出平面α，使得DE⊂α，且BF∥α，并说明理由；
（Ⅱ）求直线EF与平面BCE所成角的正弦值．
我国城镇职工医疗保障费用的来源是（ ）
阅读下列短文，从每小题的三个选项中选出最佳答案
It is morning now. Look at the sun, it rises in the east(东方). Look at the tree, the shadow is long. It is noon now. The sun is high in the sky. It is very hot. Look at the tree. The shadow is short. It is evening now. The sun goes down in the west(西方). Look at the tree, the shadow is long again. It is night now. The moon is high in the sky. There are some stars in the sky too.
“朝奉”本为官名，有些徽商是由仕而贾的，他们不愿人们称其为“老板”，而代之以“朝奉”。久之，到明末，世人统称徽商为“徽州朝奉”徽商不愿被称为“老板”这从本质上反映出（ ）
It is noon now. The sun is high in the sky. It is very hot. Look at the tree. The shadow is short. 
It is evening now. The sun goes down in the west(西方). Look at the tree, the shadow is long again. 
It is night now. The moon is high in the sky. There are some stars in the sky too. 
