3. This method has cheap instruments, simple operation, strong specificity, and no cold chain is required for actual transportation, which is conducive to popularization and promotion.
3, the method instrument cheap, simple operation, strong specificity, the actual transport does not need a cold chain, is good for popularization and promotion.
3. This method has the advantages of cheap instrument, simple operation, strong specificity and no need of cold chain in actual transportation, which is conducive to popularization and popularization.<br>