Question

シュガー

訳を教えてください。asとdoneとtheyがわからないです。

A warming Arctic ¢ould cause serious climate change elsewhere. The world's winds are
5
on場所
driven by the temperature difference between the poles and the tropics. If the Arctic heats
20
faster than the tropics, this difference will decrease and wind speeds will slow
as they
1、
have done, in the northern hemisphere, by between 5 ánd 15% in the past 30 years. A
weaker northern jet stream* will mean snowstorms and heatwaves in(
) places at (
times.

A(@
B[O
下線部(4)の they と done が具体的に表すことを明らかにして日本語に直しなさい。★
4
6 下線部(5)の2つの空欄には同じ単語が入る。最も適切なものを選びなさい。
ロ