D
考查介词。on the point of doing sth.是固定搭配,另外注意这个句子中并列连词when连接的固定句型:on the point of doing...when...,意思是“正要干……这时……”,这样的句型还有 be about to do...when...,was doing...when...。
D
考查介词。on the point of doing sth.是固定搭配,另外注意这个句子中并列连词when连接的固定句型:on the point of doing...when...,意思是“正要干……这时……”,这样的句型还有 be about to do...when...,was doing...when...。