选择下列词汇的同义词。

direct

答案 1
singly

答案 2
sum up

答案 3
blast

答案 4
passionate

答案 5
obstruction

答案 6
frequently

答案 7
principal

正确答案是：direct → instruct, singly → solely, sum up → summarize, blast → pop, passionate → enthusiastic, obstruction → obstacle, frequently → on regular basis, principal → chief