One major problem remained to be solved before it could be put to the test - a practical method of insect sterilization had to be found.
One major problem remained to be solved before it could be put to the test - a practical method of insect sterilization had to be found.
这个建议遇到来自墨守成规的官僚机构的阻力，也受到科学家的怀疑，但尼普林博士却始终没有放弃这个想法。