单项选择题
A. seriously examine present perils B. carefully choose their life partners C. immediately decide how to survive D. consciously prepare for emergencies
A. needs to be ensured to continue B. will keep on for many years C. has been unknown to scientists D. enables the locals to live a carefree life
A. had a new goal in life B. felt sad about fighting wars C. decided to pursue his studies D. expressed deep regret for his choice