Which four types of instructions take the longest time to execute? Floating-point operation instruction, string operation instruction, branch jump instruction, big data transmission instruction.

1. Floating-point operation instruction: Floating-point operation instruction needs more complicated mathematical calculation, so it needs more clock cycles to complete and takes a long time to execute.

2. String operation instruction: String operation instruction processes a large amount of character data and takes a long time to execute.

3. Branch-and-jump instruction: Branch-and-jump instruction changes the execution flow of the program according to the specific situation, which requires more clock cycles and computing resources to complete.

4. Big data transmission instructions: Big data transmission instructions transmit a large amount of data from one place to another, which requires more clock cycles and computing resources to complete.