Among simple $$LR (SLR) ,$$ canonical $$LR,$$ and look-ahead $$LR$$ $$(LALR),$$ which of the following pairs identify the method that is very easy to implement and the method that is the most powerful , in that order?

Two hosts are connected via a packet switch with $${10^7}$$ bits per second links. Each link has a propagation delay of $$20$$ micro-seconds. The switch begins forwarding a packet $$35$$ microseconds after it receives the same. If $$10000$$ bits of data are to be transmitted between the two hosts using a packet size of $$5000$$ bits, the time elapsed between the transmission of the first bit of data and the reception of the last bit of the data in microseconds is____________.

Consider a CSMA/CD network that transmits data at a rate of 100 Mbps (10⁸ bits second) over a 1 km(kilometer) cable with no repeaters. If the minimum frame size required for this network is 1250 bytes, what is the signal speed (km/sec) in the cable?

Consider a network connected two systems located 8000 kilometers apart. The bandwidth of the network is 500 × 10⁶ bits per second. The propagation speed of the media is 4 × 10⁶ meters per second. It is needed to design a Go-Back-N sliding window protocol for this network. The average packet size is 10⁷ bits. The network is to be used to its full capacity. Assume that processing delays at nodes are negligible. Then the minimum size in bits of the sequence number field has to be ___________.