Complex sentence: A sense amplifier is essentially a pair of cross-connected inverters between the bit lines, with the first inverter connected from the + bit line to the − bit line, and the second from the − bit line to the + bit line.
Split into simpler sentences: A sense amplifier is essentially a pair of cross-connected inverters between the bit lines. That is, the first inverter is connected from the + bit line to the − bit line, and the second is connected from the − bit line to the + bit line.