19

Biologists from Harvard tested the animals to find how stress affected
them. Scientists found that stress turns hair grey in mice. The scientists injected them with an ingredient taken from chili
peppers. Their hair quickly turned white.
«Scientists found that stress turns hair grey in mice» - Ученые обнаружили, что стресс вызывает седину у мышей. (mouse – мышь, mice - мыши) (Единственное и множественное)

MOUSE

20

People have believed that stress turns hair grey for centuries. France’s Queen Marie Antoinette’s hair supposedly turned white before death. More recently, the hair of presidents have quickly lost colour.
«People have believed that stress turns hair grey for centuries» - На протяжении веков люди верили (и верят), что из-за стресса волосы седеют. (когда-то начали верить и верят до сих пор) (Present Perfect)

BELIEVE

21

The researcher says the damage is permanent. They did not find a way to reverse the loss of the colour during the test last year.
«They did not find a way to reverse the loss of the colour during the test last year» - Они не нашли способа обратить вспять потерю цвета во время прошлогоднего теста. (тогда не нашли) (Past Simple – простое прошедшее)

NOT FIND

22

Cooking has reached new heights. Astronauts on the International Space Station made the first space-baked cookies. The cookies are the very first kind of food to be baked in space from raw ingredients. Baking the cookies was not as easy as the astronauts thought / had thought it would be. The first cookie came out undercooked.
«Baking the cookies was not as easy as the astronauts thought / had thought it would be» - Испечь печенье оказалось не так просто, как думали/думали астронавты. (они могли подумать об этом событии до или после этого события, поэтому два вариант возможны) (Past Simple / Past Perfect)

THINK

23

Space food is made on Earth. It is pre-packaged and then heated on the space station.
«Space food is made on Earth.» - Космическую еду производят на Земле. (вообще, общее утверждение) (Present simple Passive)

MAKE

24

Astronauts will enjoy eating freshly baked food. It will be a nice reminder of home. They said this would be important for astronauts going to the moon or on the long journey to Mars.
«Astronauts will enjoy eating freshly baked food» - Космонавтам понравится есть свежеиспеченную еду. (наслаждалась процессом) (Participle I - причастие )

EAT