1．Blood samples were sent to the laboratory for careful analysis (分析)．
2．Assuming (假设) you have a chance to go abroad, what would you do?
3．You should be aware that what you are doing is of great significance (重要意义)．
4．He has kept on learning English by radio for three years without interruption (中断)．
5．As is known to us all, accuracy (精确) is of great importance in the study of science.
6．Delete (删除) the things that you don't really need, so you can save a lot of resources.
7．My grandma still has very acute (敏锐的) hearing, though she is eighty.
8．If he takes on this work, he will have no alternative (选择) but to meet an even greater challenge.
9．As we all know, most of us middle school students feel somehow (不知怎么地) nervous whenever we're taking an important exam.
10．What's worse, they spat/spit (吐痰) and even threw rubbish into the lake, totally ignoring the noticeable sign “No Littering” nearby.
