筛分机械的振动特性与工艺参数主要包括频率与振幅、（）、筛面的长宽比值和筛面倾角等四大要素。
参考答案：抛射角与抛射强度
—Robert, I failed again!
—Don’t worry, you’ll get chosen for the team. ___________.
A．Every dog has its day.
B．A new broom sweeps clean.
C．A cat may look at a king.
D．A person is known by the company he keeps.
