采用两个38mm的普通合页(铰链)安装窗扇18扇，用多少16×3的木螺钉
参考答案：[解] 4×2×18=144个 [答] 要用144个木螺钉。
81，64，49，36，______，______．
The Direct Method got its name from the assumption that meanings are to be connected directly with ______, without going through the process of translating into the students' native language.
A. the first language B. the native languageC. the target language D. the learner's language
