knockback的复数形式怎么写？

knockback的音标：knockback的英式发音音标为：[nɒk'bæk]knockback的美式发音音标为：[nɒk'bæk]...

I must have made more than 100 phone calls and I didn't get a single knockback.我一定已经打过100多个电话了，而且还没遭到过拒绝。It'should now roughly knockback the correct length of 20 yards.现在它会正常击退20码了....

n.拒绝，震退，击退术...