Questions

With demand paging, a page is brought into memory only when a location on that page is actually referenced during execution. With pre-paging, pages other than the one demanded by a page fault are brought in. The selection of such pages is done based on common access patterns, especially for secondary memory devices.

When the letters are arranged in the alphabetical order, two remains the same.

B2+ is a Paramagnetic. 

The filled orbitals are σ(1s)22, σ∗(1s)22, σ(2s)22, σ∗(2s)22. The half-filled orbitals are π(2pxx) and π(2pyy). Since it posses 2 unpaired electrons, it is Paramagnetic in nature.

The device required for the internet connection is a MODEM.

A modem (modulator–demodulator) is a network hardware device that modulates one or more carrier wave signals to encode digital information for transmission.