神经节细胞膜上的受体是
A．β1B．β2受体C．M受体D．N1受体E．N2受体
参考答案：D
Which of the following is NOT considered a constraint when preparing an investment policy statement（）
A. Liquidity needs.
B. Time horizon.
C. Risk tolerance.
影响豪猪开棉机开松除杂的主要因素？
