用起动机启动发动机时，每次不能超过（）秒。
A.5
B.10
C.15
参考答案：A
.
It took him a few hours ________ English while I spent a few hours _____ Chinese.
A reading , to read B to read , reading C read ,read D reads ,reading
百合目中有15个科，其中百合科和鸢尾科的主要区别在于百合科子房（），雄蕊（）枚
