随地吐痰易传播疾病，痰形成于（ ）
A：咽
B：喉
C：气管
D：口腔
(____) Ottawa is the capital city of Canada.
(____) The CN Tower is very tall.
(____) It has five yellow stars.
(____) They speak English and French.
(____) I live in China.
斯大林决定实行农业全盘集体化的主要目的是
