A：2
B：12
C：﹣ 12
D：﹣2
蝗虫的若虫能够跳跃，又称为____．若虫经过____蜕皮发育成有翅能飞的成虫．
下列运算不正确的是（ ）
At the beginning of the 20th century, many people thought that the family was falling apart—__________, they thought it was dying． （ ）
