现代民航客机所使用的轮胎为().
A、有内胎的轮胎
B、无内胎的轮胎
C、高压轮胎
D、B+C
参考答案:D
Though our city has a good public transport system, _______ private car is becoming _________ popular means of transport.
A.a; /
B.the; the
C.the; a
D./; the
急性白血病与慢性白血病最主要的区别是()
A.病程的长短
B.贫血的程度
C.骨髓白血病细胞所处的阶段
D.出血程度
E.外周血白细胞数目的多少