引起以骨关节和肌肉系统病损为主的局部振动频率的主要范围是()。
A.<40Hz
B.40~300Hz
C.<20Hz
D.20~40Hz
E.>300Hz
参考答案:B
学校的各个特长俱乐部要招生。今天,有两个好朋友Mario和Lisa一起去参加面试,请完成下面主考老师与他们之间的对话。
Teacher: (1) _________________________
Mario, Lisa: We want to join the music club.
Teacher: (2) __________________________
Mario: I can sing.
Teacher: (3)____________________________
Lisa: Yes, I Can also play the piano, but I can't play it very well.
Teacher: (4) ____________________________, Mario?
Mario: Yes, I can also play the guitar.
Teacher: (5)___________________________
Mario: Sorry, I can't play it very well.
WWW服务使用的协议为()
A.HTML
B.HTTP
C.SMTP
D.FTP