谷类食物碳水化合物存在的主要形式为淀粉，以（）为主。
A.直链淀粉
B.支链淀粉
C.变性淀粉
D.糊化淀粉
参考答案：B
There comes a time in every man's life_____.
A．that he needs to think
B．when he has to think
C．therefore he has to work hard
D．then he will need it
示功图测试前应检查抽油机的（）是否灵活好用。
A、电流
B、润滑
C、刹车
D、电压
