What can we infer from the last paragraph？
A. People should practice random kindness to those in need.
B. People who receive kindness are likely to offer it to others.
C. People should practice random kindness to strangers they meet.
D. People who receive kindness are likely to pay it back to the giver.
影响免疫浊度分析的重要因素
A. 温育系统故障
B. 伪浊度
C. 边缘效应
D. 携带污染
E. 比色系统故障
IgA缺乏常伴有哪类IgG亚类的缺陷
A. IGGL
B. IGG2
C. 1GG3
D. ISCA
E. 总ISG
Jack was late because his car______halfway on the road.
A. broke down
B. broke away
C. broke through
D. broke out
微信支付 
支付宝支付