We call ____________ a bird. [ ]
A. it
B. its
C. it's
答案：A
________ salad does he want? [ ]
A. How many
B. How much
C. Where
D. Which
晚期流产是指流产发生于（）
A.妊娠12周至不足14周
B.妊娠12周至不足24周
C.妊娠12周至不足27用
D.妊娠12周至不足28周
E.妊娠24周至不足32周
