there______convenient transport in most cities in China A are B is

there______convenient transport in most cities in China A are B is
there______convenient transport in most cities in China A are B is

there______convenient transport in most cities in China A are B is
B.there be句型的就近原则

B

transport 不可数 （没写transport 就已经提示你单数还是复数了)
所以选b

is
就近原则 交通是不可数名词