1. Guatemala has declared three days of national mourning after at least 25 people were killed in one of the largest volcanic eruptions in recent years.
at least 至少
I resolved to visit my grandmother at least once a year.
我决定每年至少要去看望祖母一次 。
2. At least one village near Fuego Volcano has been buried in ash and lava. Emergency crews haven't been able to reach others.
be able to do sth 有能力做某事
What should the system be able to do?
系统应该能够有哪些功能?