燃油直接喷射式系统与汽化器系统相比突出的一大优点是（）
A.热发动机容易起动
B.不容易产生气塞现象
C.能较好地为汽缸分布燃油
参考答案：C
_______he is good at playing basketball, he failed to join the school basketball team yesterday.
A．Since
B．Unless
C．Though
D．Because
收费员上岗前应做哪些准备？
