问题补充：
The lecture was so complex that I simply couldn’t at all. Could you explain it to me?
A. bring on
B. bring in
C. take on
D. take in
答案：
A. bring on
B. bring in
C. take on
(答案→)D. take in
解析：A. bring on呈现…， 使出现，使发作，B. bring in引进，赚钱，C. take on呈现，雇佣，承担，D. take in理解，欺骗，句意：这个讲座是如此负责，以至于我根本不能理解，你能向我解释一下吗？根据句意选D。
