羊毛尾线虫病是由毛尾科、毛尾属的线虫寄生于家畜______所引起的疾病( )。
A．大肠
B．小肠
C．胃
D．肝脏
E．肾脏
参考答案：A
—Did you catch the early bus this morning?
—No.It had left the stop _____ I arrived there.[ ]
A. as soon as
B. as the time
C. by the time
D. during the time
一般来说，柴油机的指示热效率高于汽油机，四冲程发动机的指示热效率高于二冲程发动机。
