简述文学理论任务4方面。
参考答案：
文学本质论、文学创作论、作品论、文学接受论。
与有机磷农药中毒相比,氨基甲酸酯中毒症状是
A．快,而轻B．慢,但严重C．急,而严重D．慢,而轻E．二者相同
There is a 30% chance that the economy will be good and a 70% chance that it will be bad. If the economy is good, your returns will be 20% and if the economy is bad, your returns will be 10%. What is your expected return（）
A. 15%.
B. 17%.
C. 13%.
