第三人称单数： cans

复数： cans

现在分词： canning

过去式： could

过去分词： could 扩展资料

When can I get my test results?

我什么时候可以拿到化验结果

We can reduce the problem to two main issues.

我们可以将这个问题概括成两个要点。

The operation could prolong his life by two or three years.

这次手术可使他多活两三年。