다음 글의 빈칸 (A), (B)에 들어갈 말로 가장 적절한 것은? Fi… | [법원직 9급 영어] 16년 1회차 기출문제 상세 페이지

다음 글의 빈칸 (A), (B)에 들어갈 말로 가장 적절한 것은? 
Fifty years ago, bees lived healthy lives in our cities and rural areas because they had plenty of flowers to feed on, fewer insecticides contaminating their floral food and fewer exotic diseases and pests. Wild bees nested successfully in undisturbed soil and twigs. (A), bees have trouble finding pollen and nectar sources because of the extensive use of herbicides that kill off so many flowering plants among crops and in ditches, roadsides and lawns. Flowers can be contaminated with insecticides that can kill bees directly or lead to chronic, debilitating effects on their health. (B), with the increase in global trade and transportation, blood-sucking parasites, viruses and other bee pathogens have been inadvertently transmitted to bees throughout the world. These parasites and pathogens weaken bees' immune systems, making them even more susceptible to effects of poor nutrition from lack of flowers, particularly in countries with high agricultural intensity and pesticide use.

However / … / As a result

However / … / In addition

Thus / … / By contrast

Thus / … / On the other hand