David worked hard at his lessons ____ he gained high grades in the exams.
| A．so that | B．in order to | C．though | D．because |
强调、倒装与省略（句）
. It was ________ he studied that he managed to receive a doctor’s degree.
| A．that | B．because | C．on account of | D．due to |
.Growing around the river ________ wild flowers of almost the same colour.
| A．is | B．was | C．are | D．has been |
. A variety of courses ________ offered to enrich the students’ background knowledge of the English-speaking countries.
| A．were | B．is | C．have | D．has E) / |
. Though having a big market share, most electronic devices of this kind/type/sort ________ found poor in quality.
| A．is | B．being | C．are | D．having been |
E) has F) have G) / H) is being
. Statistics ________ that most of the published and quoted scientific articles are related to medical science.
| A．has shown | B．is shown | C．show | D．shows |