4. Please translate the following paragraph into Mandarin. Double-stranded breaks (DSBs) in DNA arise frequently. If these breaks are not repaired, the consequence to the cell is disastrous. For example, a single DSB in the Escherichia coli chromosome is lethal to a cell that lacks the ability to repair it. The major mechanism used to repair DSBs in most cells is homologous recombination. Some cell types also use a simpler mechanism, such as nonhomologous end joining (NHEJ) to heal their chromosomes.