单项选择题
Do you want to buy（）pork？
A.half kilo B.half a kilo C.a kilo half D.a half kilo
单项选择题 The days are short，（）it is now December.
单项选择题 （）number of students have gone to Shanghai.
单项选择题 ——（）they（）an English class？ ——N0.they aren’t.
