食管癌的典型症状是
A．进食时易哽噎B．进行性厌食C．胸骨后烧灼感D．进行性吞咽困难E．胸背部疼痛
参考答案：D
--- Do you know what Millie and Andy were doing at 8 o’clock yesterday?
--- As Millie_____ TV, Andy _____ the door to welcome Tom.
A．was watching: was opening
B．watched; opened
C．was watching; opened
D．watched: was opening
