Сделайте по примеру:
Miss A.:"Buy a thick red pencil."
Miss B.:"Buy thick red pencils."

в 3-ем предложении вместо this можно было написать these, но думаю это не имеет значения. Можно и так, и так!

Спасибо вам онромное) очень помогли

Рада помочь! Welcome)

1 Take pens and write down the new words.2 Drow black cats with bushy tails.3 You need brushes and some plack paint to do this.4 You must be hungry, have sandwiches.5 I was very touched when you gave me flowers on my birthday.6 Please bring chairs from the room next door.7 I want you to choose good books and read them during your holidays.8 Don't forget to write greeting cards to your grandparents and post them well before the holiday.