Thenewdiscovery_______beofgreatservicetomankind.
A、isboundto
B、isboundfor
C、beboundto
D、beboundfor
_______foryourlaziness，youcouldhavefinishedtheassignmentbynow.
A、Haditnotbeen
B、Itwerenot
C、Weren’tit
D、Hadnotitbeen
Nosoonerhadwereachedhome________aviolentstormbrokeout.
A、when
B、that
C、until
D、than
Theyareeager_______abroad.
A、travel
B、travelled
C、totravel
D、travelling
A、满足不孕妇女养育孩子的正当愿望
B、满足代理母亲乐意助人的良好愿望
C、代孕是一种合作生殖
D、代孕可能引起的商业化问题可以通过管理解决