生化汤主治证的病机是
A．热与血结B．血虚受寒C．气虚血滞D．冲任虚损E．血瘀气滞
参考答案：B
At first, I found ____ very hard to learn English by myself. [ ]
A. it
B. it's
C. that
D. that's
土壤满足生物对水、肥、气、热要求的能力称为______。
