As is already discussed,the disease,if present at all,is usually a rather steady and continuous process. ·已如上述，一旦此病发生，其病程通常稳 定而持久。 ● 已如上述，一旦此病发生，其病程通常顽 固而持久。⚫ As is already discussed, the disease, if present at all, is usually a rather steady and continuous process. ⚫ 已如上述，一旦此病发生，其病程通常稳 定而持久。 ⚫ 已如上述，一旦此病发生，其病程通常顽 固而持久