人感染高致病性禽流感的主要传染源为()
A.流感患者和隐性感染者
B.患禽流感或携带病毒的鸡、鸭等禽类
C.与鼠类密切接触
D.A、B均可
E.A、B均不可
参考答案:B
用所给单词的适当形式填空
1. It is said that he has____(accumulate)a large fortune.
2. Would it be____ (convenience) for you to pick me up at 2 p.m. and take me to the railway station?
3. In the bard times ,she____(bear)the pain with great courage.
4. Generally speaking, green is usually____(associate) with life.
切边剪剪切钢带,最大剪切厚度()㎜;
A.3
B.4
C.5
D.6