说明原因型模块
These dayswe often hear that...
(1).It is common that...
(2). Why does such circumstance occurin spite of social protects? For one thing...
(3).For another...
(4). What is more,since...
(5).it isnatural that...
(6).To solve the problem is not easy at all, but is worth trying.We should do something such as...
(7). to improve he present situation, and I do believe everything will be better in the future.