当太阳风暴到达地球时，地球上具有可降低太阳活动对其影响的保护层是（ ） ①水圈 ②大气圈 ③岩石圈 ④地球磁场
A：①②
B：①③
C：①④
D：②④
— Why did she ______ your invitation?
— Because she had an important meeting to attend that day.
爱心是一片照射在冬日里的阳光，使贫病交迫的人感到人间的温暖；
爱心是____，____。
young（反义词）____
