自动返航的安全高度无法更改。
参考答案：错
In some cities, the junior pupils look forward to having ______ time to relax and ______ homework to do.
A．less; more
B．more; less
C．fewer; more
D．much; many
肺栓塞的栓子大多数来源于
A．右心室
B．右心房
C．下肢浅静脉
D．深静脉
E．肺动脉内
