30. I always check the prices of different brands _____ I make a major purchase.
A
before
B
because
C
although
D
where
24. I wonder whether his hearing is okay ______ he has turned the television up very loud.
27. You’d better make the plants shorter, ______ they will interrupt the views from the house.
21. The ceiling’s low, _____ you need to be careful not to hit your head.
句意:在我购买之前,我总是会检查不同品牌的价格。根据句意可知应用before.故选A。
连词
判断结构
抓不住要点
容易