He became very weak towards the end of his life.
他临终时很虚弱。
He was a weak little mouse of a man.
他是个懦弱无能的.人。
I was always weak in the science subjects.
我总是学不好理科。
That bridge is too weak for heavy traffic.
那座桥不太牢固，承受不住过多的车辆。
The unions have always been weak in this industry.
在这个行业，工会一直没有权威。