In school, he was not one of the achievers.

　　上學時他不屬于拔尖的那類。

　　The two groups of children have quite different characteristics.

　　這兩組兒童具有截然不同的特點。

　　The project is still causing him a lot of problems.

　　這項工程現(xiàn)在仍然給他帶來許多的麻煩。

　　The need to communicate is a key characteristic of human society.

　　需要交流是人類社會最重要的一個特征。

　　The new test should aid in the early detection of the disease.

　　新的化驗應該有助于早早檢查出這種疾病。