A：
B：
—John didn't stop looking for a job _________ he got an offer from a German company.
—Lucky him. It's not easy for university graduates to get a good job now.
蝗虫的发育要经历卵、若虫、成虫三个时期，若虫与成虫的区别主要是表现在（ ）。
促胰液素和促甲状腺激素的靶细胞分别是（ ）
