文8課 「は・が」の使い分け 教科書 p.148〜151
Distinguishing は and が — new/old information, opposition, implementation
用法：主題を は、その属性を が
State the topic with は, then talk about a part/attribute of it with が.
注意 / Note：The part 「〜は」 is often omitted by when it is clear from the context - exam questions often exploit this place.
比較 / Compare：〜は〜が（topic ＋attributes）；section 〜は is often overlooked by when it is clear.
よく出る形 / Common form：名＋は＋名＋が＋形容詞／述語.
今日の研修会は内容が盛りだくさんで、終わったのは5時過ぎだった。
Today's training session is packed with content, ending at more than 5 o'clock.
省エネ機能が優れている製品は電気代が安くて済む。
Products with good electricity saving features have cheap electricity bills.
この製品は値段が手ごろだ。
This product is affordable.