解：∵AB=2cm，BC=2AB，

∴BC=4cm．

∴AC=AB+____=____cm．

∵D是AC的中点，

∴AD= $\frac{1}{2}$ ____=____cm．

∴BD=AD﹣____=____cm．

根据句意和提示写出单词，完成句子.
(1)The iPhone 5 is one of the ____ (参观者). He is looking for it everywhere
(2)I'm sorry that the dog you once played a trick on ____  (攻击) you .
(3)Turn on your TV, and you can see Chairman Xi____  (接受) the interview of the reporter from CCTV now.
(4)The fourth day of the week is____  (星期三).
(5)When I passed the finishing line, my teacher cheered with____  (激动的)look.
(6)We are ____  (true)proud of our woman astronaut,Wang Yaping.
(7)Shao Yifu's great ____  (achieve) is never going to be forgotten.
(8)Peng Liyuan is a woman of great charm, she has an____  (attract) quality.
(9)About three____ (twenty) of the doctors in the hospital are women.
(10)When a strong wind came from the northwest, the heavy haze(雾霾) in Yancheng began to____  (appear).  

人在呼气时，膈肌舒张，膈的顶部（　　）