居住区公共绿地常见的类型有：（）、居住小区小游园、组团绿地。
什么是生物安全？
冷轧是金属在（）以下进行的轧制变形。一般指（）的热轧钢卷不经加热而在室温直接进行轧制加工。
下列种间关系（）属于互利互生。 ["豆科植物与禾本科植物","豆科植物也根瘤菌","鸟与树"]
Which two statements or sets of statements are true about the application of the qos pre-classify command？（） [" If the classification policy is based upon the ToS byte， the qos pre-classify command is required because the ToS byte only appears in the inner IP header."," The ToS byte is copied to the outer header by default. Therefore， the qos pre-classify command is not necessary."," With GRE encapsulation， the qos pre-classify command is applied on the tunnel interface. This practice allows for different OoS configurations on each tunnel."," With GRE encapsulation， the qos pre-classify command is applied on the physical interface. This practice allows for different OoS configurations on each interface."," With IPsec encapsulation， the qos pre-classify command is applied on the physical interface. This practice allows for different OoS configurations on each interface."]
什么是致欢送辞？
