After Senator Smith announced that he planned to run for president, the telephone at campaign headquarters rang continuously.
Giải chi tiết:
Đáp án là B. continuously: tiếp tục >< ceasingly: tạm ngừng
Nghĩa các từ còn lại: endlessly: không ngừng; incisively: một cách sâu sắc; constantly: liên tục
Biogas can be utilized for electricity production, cooking, space heating, water heating and process heating.
Around 150 B.C. the Greek astronomer Hipparchus developed a system to classify stars according to brightness.