人类最早的教学手段是______。 A．文字材料 B．口耳相传 C．直观教具 D

We have already covered the topic of network addresses. The first （） in a block (in classes A，B，and C) defines the network address. In classes A，B，and C，if the hostid is all ls， the address is called a direct broadcast address. It is used by a.（） to send a packet to all hosts in a specific network. All hosts will accept a packet having this type of destination address. Note that this address can be used only as a （） address in an IP packet. Note also that this special address also reduces the number of available hostid for each netid in classes A，B，and C.

In classes A，B，and C，an address with all is for the netid and hostid (32 bits) defines a（） address in the current network.A host that wants to send a message to every other host can use this address as a destination address in an IP packet. However，a router will block a packet having this type ofaddress to confine the broadcasting to the （） network. Note that this address belongs to class E.

It is used by a.（） to send a packet to all hosts in a specific network.

A．router

B．switch

C．hub

D．firewall

复苏有效时，病人瞳孔的变化包括( )

A．由小变大

B．对光反射从无到有

C．对光反射从迟钝到活跃

D．由大变小

E．对光反射逐步消失

清末东北地区的行政由军事统治向民政管理的转变始于( )

A．地方督抚权力的加强

B．建立行省制度

C．特派员制度

D．盛京改制

城市经济以具有广泛分布的( )为特点，即( )不能在商品买卖的价格上反映出来。

A．外在性：经济资源的合理配置
B．内在性，成本和效益
C．外在性，成本和效益
D．内在性，经济资源的合理配置

甲国公司与中国公司就一项进出口合同的履行发生争议，并诉诸中国法院。合同未约定法律适用的内容。原告起诉的请求和主张依据中国法律，被告对此未提出异议，且援引中国法进行答辩。根据最高人民法院《关于审理涉外民事或商事合同纠纷案件法律适用若干问题的规定》，关于合同的法律适用，下列哪一选项是正确的

A．当事人只能在一审开庭前对适用的法律进行选择
B．因本案当事人在合同中未约定法律适用条款，原告不得依中国法起诉
C．本案应当采用最密切联系原则确定应适用的法律
D．本案的情况应视为当事人双方已就合同适用的法律作出了选择