they (both can) swim across the river,（）中为啥需填both can?

分类: 作业答案 • 2021-12-29 16:32:45

问题描述：

they (both can) swim across the river,（）中为啥需填both can?
有嘉奖oh
（）中为啥需填 both can
而不填can both
both不是需要放在情态动词后吗?

答

也可以填can't啊.