Внешние данные эритроциты человека

Past Simple: 1. I wrote an interesting story.2. We became friends last year.3. I saw my aunt yesterday in the shop.Past Continuous:1. She was selling vegetables in the supermarket.2. I was going to the hospital to visit my grandmother.3. My relatives were laughing at the party.Past Perfect:1. They had written an essay.2. We had done it the day before.3. Mary had chosen a new job.Past Perfect Continuous:1. She had been singing at the concert.2. Tim had been drawing a picture.3. Susan had been dancing with her boyfriend.

Эритроцит - это как бы диск, с уплощенным центром, то есть вдавленным немного