蚤为其中间宿主（）
A．黑热病原虫
B．肺吸虫
C．丝虫
D．短膜壳绦虫
E．疟原虫
参考答案：D
简述制定劳动定额应满足的要求。
_____ he was only twelve, he could run faster than any kids in the school.
A. Though B. Because C. If
